ABCMdb

ABCC7 p.Gly480Cys

ClinVar:	c.1439G>A , p.Gly480Asp ? , not provided c.1438G>A , p.Gly480Ser ? , not provided c.1438G>T , p.Gly480Cys D , Pathogenic
CF databases:	c.1439G>A , p.Gly480Asp (CFTR1) D , The above mutation was detected by SSCP and identified by direct DNA sequencing. G480D was found in a CF patient from the West Midlands, who had meconium ileus and whose other chromosome carries [delta]F508; it was seen only once in 100 non-[delta]F508 chromosome screened. c.1438G>A , p.Gly480Ser (CFTR1) ? , The mutation was detected in a 1 year old patient by multiple heteroduplex analysis on the MDE gel matrix. The patient was heterozygous for the A559T mutation. c.1438G>T , p.Gly480Cys (CFTR1) ? , This mutation was found in an American Black patient who has an unknown mutation on the other chromosome and is pancreatic insufficient. This mutation was found in one additional non-[delta]F508 CF chromosome of 378 tested. It was not found in over 700[delta]F508 chromosomes, nor in a small number of normal chromosomes.
Predicted by SNAP2:	A: D (95%), C: N (53%), D: D (95%), E: D (95%), F: D (95%), H: D (95%), I: D (95%), K: D (95%), L: D (95%), M: D (95%), N: D (95%), P: D (95%), Q: D (95%), R: D (95%), S: D (95%), T: D (95%), V: D (95%), W: D (95%), Y: D (95%),
Predicted by PROVEAN:	A: D, C: D, D: D, E: D, F: D, H: D, I: D, K: D, L: D, M: D, N: D, P: D, Q: D, R: D, S: D, T: D, V: D, W: D, Y: D,

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[hide] Insight in eukaryotic ABC transporter function by ... FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19. Frelet A, Klein M
Insight in eukaryotic ABC transporter function by mutation analysis.
FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19., 2006-02-13 [PMID:16442101]

Abstract [show]
With regard to structure-function relations of ATP-binding cassette (ABC) transporters several intriguing questions are in the spotlight of active research: Why do functional ABC transporters possess two ATP binding and hydrolysis domains together with two ABC signatures and to what extent are the individual nucleotide-binding domains independent or interacting? Where is the substrate-binding site and how is ATP hydrolysis functionally coupled to the transport process itself? Although much progress has been made in the elucidation of the three-dimensional structures of ABC transporters in the last years by several crystallographic studies including novel models for the nucleotide hydrolysis and translocation catalysis, site-directed mutagenesis as well as the identification of natural mutations is still a major tool to evaluate effects of individual amino acids on the overall function of ABC transporters. Apart from alterations in characteristic sequence such as Walker A, Walker B and the ABC signature other parts of ABC proteins were subject to detailed mutagenesis studies including the substrate-binding site or the regulatory domain of CFTR. In this review, we will give a detailed overview of the mutation analysis reported for selected ABC transporters of the ABCB and ABCC subfamilies, namely HsCFTR/ABCC7, HsSUR/ABCC8,9, HsMRP1/ABCC1, HsMRP2/ABCC2, ScYCF1 and P-glycoprotein (Pgp)/MDR1/ABCB1 and their effects on the function of each protein.

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298 Mutation of P740, 750 and 759 to alanine activated the channel by increasing the number of openings and not the Protein Relative Position Mutation Proposed function of residue and effect of mutation Experimental system Ref. CFTR G480C protein mislocalization but normal chloride channel activity. Expression in Xenopus oocytes. Login to comment

[hide] Enhancing the efficiency of introducing precise mu... Transgenic Res. 2000 Feb;9(1):55-66. Dickinson P, Kimber WL, Kilanowski FM, Webb S, Stevenson BJ, Porteous DJ, Dorin JR
Enhancing the efficiency of introducing precise mutations into the mouse genome by hit and run gene targeting.
Transgenic Res. 2000 Feb;9(1):55-66., [PMID:10853269]

Abstract [show]
The creation of precise clinical mutations by targeting is important in elucidating disease pathogenesis using mouse models. 'Hit and run' gene targeting is an elegant method to achieve this goal. This uses first a positive selection to introduce the targeting vector carrying the required mutation and then a negative selection to identify clones which have removed vector and wild-type sequences by intrachromosomal recombination. However, this approach has only been successfully used in a handful of cases. We used this procedure to introduce precise clinical mutations into the exon 10 region of the cystic fibrosis transmembrane conductance regulator (Cftr) gene. Using a CMV promoter driven hygromycin/thymidine kinase (hyg/tk) fusion gene as both our dominant and negative selectable marker, we targeted the Cftr locus very efficiently but only identified false runs after the negative selection step. This defect in thymidine kinase induced toxicity to gancyclovir correlated with methylation of the transgene. Consequently we devised a stringent screening procedure to select only true 'run' clones. Unfortunately these 'run' clones had lost the mutation so we altered the vector design to bias the run step to retain the mutation and used a different tk selection cassette with a HSVtk promoter sequence. This new vector design allowed both efficient 'hit and run' for two cystic fibrosis (CF) mutations with no false positives and successful germline transmission of the novel G480C missense mutation.

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12 This new vector design allowed both efficient 'hit and run` for two cystic fibrosis (CF) mutations with no false positives and successful germline transmission of the novel G480C missense mutation. Login to comment
26 Finally we designed a vector containing the base substitution that results in the missense mutation G480C. Login to comment
34 Using these second generation vectors, ES cells could be 'hit` even more efficiently and ES cell 'run` clones bearing the precisely introduced G480C and F508 mutations were efficiently produced. Login to comment
35 Chimaeric animals which have demonstrated their capability to transmit the G480C mutation through the germline have been generated. Login to comment
42 The G480C mutation comprised three base substitutions at positions 1440, 1441, and 1443 (wild type sequence from position 1435 TCA GAG GGA ATT, mutant sequence from position 1435 TCA GAA TGC ATT). Login to comment
43 The novel restriction sites SspI ( I507), Asp718I ( F508), and Nsil (G480C) were created along with the relevant mutations to allow screening for the presence of the mutation. Login to comment
120 The grey star labelled 0.6 represents the novel 0.6-kb fragment generated by the introduction of the G480C linked Nsi site. Login to comment
173 G480C After transfection of CGR8 cells with vector pHRG480C, 50 G418 resistant colonies were isolated and 38 analysed for targeting of the vector ('hit`) to the Cftr locus. Login to comment
175 These clones were then screened to check for retention of the introduced mutation (a silent, novel restriction site introduced with the G480C mutation) during the targeting process. Login to comment
184 These ES clones have subsequently been used for blastocyst injections to generate chimaeric mice which have demonstrated that they are capable of germline transmission of the G480C mutant allele. Login to comment
196 A similar high frequency was observed both in the vector carrying the F508 mutation and the G480C mutation. Login to comment
198 Detection and analysis of G480C 'hit and run` clones. Login to comment
202 (B) Analysis of DNA from G480C 'hit` clones to check for retention of the G480C mutation. Login to comment
203 After digestion of DNA from 'hit` clones (6.2, 8.5, 3.3, 6.4, 9.3, 3.1, and 4.2) with NsiI and probing with the 1.3XH external probe the mutant 6.1-kb band indicates the presence of the G480C mutation at the Cftr locus in clones 6.2, 8.5, and 3.3 (see Figure 1(b) (iii)) for diagram). Login to comment
205 (C) Verification that 'run` clones have retained the G480C mutation. Login to comment
207 The 6.1-kb band indicates the presence of the G480C mutation (see Figure 1(b) (iii). Login to comment
242 The fact that the 'run` clones selected in the F508 and G480C gene targeting experiments had not arisen by gene silencing rather than gene loss implied that the tk gene in these vectors was more resistant to inactivation than the fusion gene. Login to comment
245 The F508 vector with this region of DNA still had a retention to loss ratio of 1:4 but analysis of the run clones with the G480C vector revealed that the ratio of mutation retention to loss was 1:1. Login to comment
246 In conclusion, therefore, we demonstrate here that if careful vector design and culturing technique are used then the 'hit and run` strategy can be used efficiently to introduce predetermined mutations ( F508 and G480C) into murine ES cells. Login to comment
248 We have successfully used the ES cells carrying the G480C mutation to generate chimaeric mice which have gone on to demonstrate their ability to pass the G480C mutation through the germline. Login to comment

[hide] Type I, II, III, IV, and V cystic fibrosis transme... Curr Opin Pulm Med. 2000 Nov;6(6):521-9. Choo-Kang LR, Zeitlin PL
Type I, II, III, IV, and V cystic fibrosis transmembrane conductance regulator defects and opportunities for therapy.
Curr Opin Pulm Med. 2000 Nov;6(6):521-9., [PMID:11100963]

Abstract [show]
Recent advances in cellular and molecular biology have furthered the understanding of several genetic diseases, including cystic fibrosis. Mutations that cause cystic fibrosis are now understood in terms of the specific molecular consequences to the cystic fibrosis transmembrane conductance regulator (CFTR) protein expression and function. This knowledge has spawned interest in the development of therapies aimed directly at correcting the defective CFTR itself. In this article, we review the molecular defect underlying each recognized class of CFTR mutation and the potential therapies currently under investigation. Opportunities for protein-repair therapy appear to be vast and range from naturally occurring compounds, such as isoflavonoids, to pharmaceuticals already in clinical use, including aminoglycoside antibiotics, butyrate analogues, phosphodiesterase inhibitors, and adenosine nucleotides. Future therapies may resemble designer compounds like benzo[c]quinoliziniums or take the form of small peptide replacements. Given the heterogeneity and progressive nature of cystic fibrosis, however, optimal benefit from protein-repair therapy will most likely require the initiation of combined therapies early in the course of disease to avoid irreparable organ damage.

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52 Since "misfolding" of the ∆F508 CFTR and other class II mutants (eg, G480C) does not completely abolish CFTR chloride conductance [44-46], therapies can be aimed primarily at overcoming the trafficking block, thereby permitting surface expression of the partially active mutant channel. Login to comment

[hide] Improved detection of cystic fibrosis mutations in... Genet Med. 2001 May-Jun;3(3):168-76. Heim RA, Sugarman EA, Allitto BA
Improved detection of cystic fibrosis mutations in the heterogeneous U.S. population using an expanded, pan-ethnic mutation panel.
Genet Med. 2001 May-Jun;3(3):168-76., [PMID:11388756]

Abstract [show]
PURPOSE: To determine the comparative frequency of 93 CFTR mutations in U.S. individuals with a clinical diagnosis of cystic fibrosis (CF). METHODS: A total of 5,840 CF chromosomes from Caucasians, Ashkenazi Jews, Hispanics, African Americans, Native Americans, Asians, and individuals of mixed race were analyzed using a pooled ASO hybridization strategy. RESULTS: Sixty-four mutations provided a sensitivity of 70% to 95% in all ethnic groups except Asians, and at least 81% when the U.S. population was considered as a whole. CONCLUSIONS: For population-based carrier screening for CF in the heterogeneous U.S. population, which is characterized by increasing admixture, a pan-ethnic mutation panel of 50 to 70 CFTR mutations may provide a practical test that maximizes sensitivity.

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127 Of the 20 mutations that account for the overall detection rate in African Americans when ⌬F508 is excluded, nine that account for 23.6% of the chromosomes analyzed are considered to be "African" mutations6 (444delA, G330X, G480C, R553X, A559T, 2307insA, 3120 ϩ 1GϾA, 3791delC, and S1255X). Login to comment

[hide] Induction of HSP70 promotes DeltaF508 CFTR traffic... Am J Physiol Lung Cell Mol Physiol. 2001 Jul;281(1):L58-68. Choo-Kang LR, Zeitlin PL
Induction of HSP70 promotes DeltaF508 CFTR trafficking.
Am J Physiol Lung Cell Mol Physiol. 2001 Jul;281(1):L58-68., [PMID:11404246]

Abstract [show]
The DeltaF508 cystic fibrosis transmembrane conductance regulator (CFTR) is a temperature-sensitive trafficking mutant that is detected as an immature 160-kDa form (band B) in gel electrophoresis. The goal of this study was to test the hypothesis that HSP70, a member of the 70-kDa heat shock protein family, promotes DeltaF508 CFTR processing to the mature 180-kDa form (band C). Both pharmacological and genetic techniques were used to induce HSP70. IB3-1 cells were treated with sodium 4-phenylbutyrate (4PBA) to promote maturation of DeltaF508 CFTR to band C. A dose-dependent increase in band C and total cellular HSP70 was observed. Under these conditions, HSP70-CFTR complexes were increased and 70-kDa heat shock cognate protein-CFTR complexes were decreased. Increased DeltaF508 CFTR maturation was also seen after transfection with an HSP70 expression plasmid and exposure to glutamine, an inducer of HSP70. With immunofluorescence techniques, the increased appearance of CFTR band C correlated with CFTR distribution beyond the perinuclear regions. These data suggest that induction of HSP70 promotes DeltaF508 CFTR maturation and trafficking.

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281 Whether this approach would also overcome the defects caused by other trafficking mutants such as N1303K, P574H, or G480C remains to be tested. Login to comment

[hide] Analysis of exocrine pancreatic function in cystic... Eur J Clin Invest. 2001 Sep;31(9):796-801. Walkowiak J, Herzig KH, Witt M, Pogorzelski A, Piotrowski R, Barra E, Sobczynska-Tomaszewska A, Trawinska-Bartnicka M, Strzykala K, Cichy W, Sands D, Rutkiewicz E, Krawczynski M
Analysis of exocrine pancreatic function in cystic fibrosis: one mild CFTR mutation does not exclude pancreatic insufficiency.
Eur J Clin Invest. 2001 Sep;31(9):796-801., [PMID:11589722]

Abstract [show]
BACKGROUND: Cystic fibrosis (CF) is the most common cause of exocrine pancreatic insufficiency in childhood. The aim of the present study is to evaluate the correlation between genotype and exocrine pancreatic insufficiency in CF patients. The special emphasis was put on the analysis of mild CFTR mutations. DESIGN: The study comprised 394 CF patients and 105 healthy subjects (HS). Elastase-1 concentrations were measured in all subjects. RESULTS: Severe pancreatic insufficiency was associated with the presence of two CFTR gene mutations (DeltaF508, N1303K, CFTR dele 2,3 (21kb), G542X, 1717-1G-A, R533X, W1282X, 621GT, 2183AAG, R560T, 2184insA and DeltaI507, G551D, 895T) and mild insufficiency with the presence of at least one mutation (R117H, 3171insC, A155P2, 138insL, 296 + 1G-A, E92GK, E217G, 2789 + 5G-A. 3849 + 1kbC-T/3849 + 1kbC-T) genotype resulted in high elastase-1-values. However, in case of patients with genotype DeltaF508/3849 + 10kbC-T, 1717-1GA/3849 + 10kbC-T as well as with DeltaF508/R334W, both high and low elastase-1 concentrations were found. Low E1 values were found in a patient with DeltaF508/R347P genotype. CONCLUSION: Patients who carry two 'severe' mutations develop pancreatic insufficiency, whereas those who carry at least one 'mild' usually remain pancreatic sufficient. However, the presence of one mild mutation does not exclude pancreatic insufficiency.

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86 Kristidis et al. [10] reported that pancreatic insufficiency strongly correlates also with two alleles of DI507, Q493X, G542X, R553X, W1282X, 621 1 1G-T, 1717±1G-A, 556delA, 3659delC, I148T, G480C, V520F and R560T while one or two mutations such as R117H, R334W, A455E, and P574H were correlated with a pancreatic sufficient phenotype. Login to comment

[hide] The severe G480C cystic fibrosis mutation, when re... Hum Mol Genet. 2002 Feb 1;11(3):243-51. Dickinson P, Smith SN, Webb S, Kilanowski FM, Campbell IJ, Taylor MS, Porteous DJ, Willemsen R, de Jonge HR, Farley R, Alton EW, Dorin JR
The severe G480C cystic fibrosis mutation, when replicated in the mouse, demonstrates mistrafficking, normal survival and organ-specific bioelectrics.
Hum Mol Genet. 2002 Feb 1;11(3):243-51., 2002-02-01 [PMID:11823443]

Abstract [show]
The majority of cystic fibrosis patients produce a mutant form of CFTR (DeltaF508) which has been shown to be mislocalized in both humans and mice. G480C, another clinically 'severe' mutation, has also been demonstrated to be defective in its intracellular processing, but when allowed to traffic in Xenopus oocytes showed similar channel characteristics to that of wild-type CFTR. We have replicated the G480C mutation in the murine Cftr gene using the 'hit and run' double recombination procedure. As expected, the G480C cystic fibrosis mouse model expresses the G480C mutant transcript at a level comparable to that of wild-type CFTR: The homozygous mutant mice were fertile, had normal survival, weight, tooth colour and no evidence of caecal blockage, despite mild goblet cell hypertrophy in the intestine. Analysis of the mutant protein revealed that the majority of G480C CFTR was abnormally processed and no G480C CFTR-specific immunostaining in the apical membranes of intestinal cells was detected. The bioelectric phenotype of these mice revealed organ-specific electrophysiological effects. In contrast to DeltaF508 'hit and run' homozygotes, the classic defect of forskolin-induced chloride ion transport is not replicated in the caecum, but the response to low chloride in the nose is clearly defective in the G480C mutant animals. The mild phenotype of these G480C mutant animals combined with the defective chloride transport in the nose uniquely provides a valuable resource to test novel pharmacological agents aimed at improving trafficking and correcting the electrophysiological defect in the respiratory tract.

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2 3 243-251 The severe G480C cystic fibrosis mutation, when replicated in the mouse, demonstrates mistrafficking, normal survival and organ-specific bioelectrics Paul Dickinson, Stephen N. Smith1, Sheila Webb, Fiona M. Kilanowski, Isla J. Campbell, Martin S. Taylor, David J. Porteous , Rob Willemsen2, Hugo R. de Jonge3, Ray Farley1, Eric W. F. W. Alton1 and Julia R. Dorin* MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK, 1Department of Gene Therapy, National Heart and Lung Institute at Imperial College, London, UK, 2CBG-Department of Clinical Genetics and 3Department of Biochemistry, Faculty of Medicine and Health Sciences, Erasmus University, PO Box 1738, 3000 DR Rotterdam, The Netherlands Received September 13, 2001; Revised and Accepted November 23, 2001 The majority of cystic fibrosis patients produce a mutant form of CFTR (∆F508) which has been shown to be mislocalized in both humans and mice. Login to comment
3 G480C, another clinically 'severe` mutation, has also been demonstrated to be defective in its intracellular processing, but when allowed to traffic in Xenopus oocytes showed similar channel characteristics to that of wild-type CFTR. Login to comment
4 We have replicated the G480C mutation in the murine Cftr gene using the 'hit and run` double recombination procedure. Login to comment
5 As expected, the G480C cystic fibrosis mouse model expresses the G480C mutant transcript at a level comparable to that of wild-type Cftr. Login to comment
7 Analysis of the mutant protein revealed that the majority of G480C CFTR was abnormally processed and no G480C CFTR-specific immunostaining in the apical membranes of intestinal cells was detected. Login to comment
9 In contrast to ∆F508 'hit and run` homozygotes, the classic defect of forskolin-induced chloride ion transport is not replicated in the caecum, but the response to low chloride in the nose is clearly defective in the G480C mutant animals. Login to comment
10 The mild phenotype of these G480C mutant animals combined with the defective chloride transport in the nose uniquely provides a valuable resource to test novel pharmacological agents aimed at improving trafficking and correcting the electrophysiological defect in the respiratory tract. Login to comment
16 Other 'severe` mutations have been described and G480C is one where an amino acid substitution occurs in exon 10 of CFTR (3). Login to comment
17 Both G480C and ∆F508 mutations show a primary defect in protein processing and trafficking, such that mutant protein is retained and degraded in the endoplasmic reticulum, resulting in a severe reduction at the plasma membrane (4-6). Login to comment
18 When expressed in Xenopus oocytes (where the transport block can be overcome), the G480C protein has an apical plasma membrane Cl-channel activity identical to that of wild-type CFTR (6). Login to comment
20 We created mutant mice that carry the G480C mutation by gene targeting using the 'hit and run` technique (10,11). Login to comment
30 In this study, an accurate mouse model of the G480C mutation was used to assess the phenotype of another 'severe` CF mutation in vivo and to clarify the organ-specific consequences of a mistrafficking mutant. Login to comment
31 RESULTS Generation of Cftrtm2Hgu mice which carry the G480C mutation ES cells modified at the Cftr locus to possess the G480C mutation in exon 10 by 'hit and run` gene targeting have previously been described by Dickinson et al. (11). Login to comment
32 Four ES cell clones modified to possess the G480C mutation which had normal karyotypes were used for blastocyst injections. Login to comment
34 Homozygous G480C mutant mice are designated Cftrtm2Hgu following the Mouse Nomenclature Committee guidelines. Login to comment
35 A novel NsiI restriction enzyme site was created at the site of the G480C mutation (Fig. 1A) and restriction enzyme digestion verified the faithful replacement of the wild-type exon 10 with the mutant exon 10 (Fig. 1B-D). Login to comment
37 Generation of G480C Cftr mutant mice by 'hit and run` gene targeting. Login to comment
46 Wild-type Cftr genomic structures are shown for strains 129, in which gene targeting was performed, C57 Bl/6, which was used for subsequent breeding, and 129/G480C 'hit and run` gene targeted locus. Login to comment
48 (C) Germline transmission of the Cftr G480C allele. Login to comment
50 B, C57 Bl/6 offspring; C, CGR8 parental ES cells; E, G480C targeted ES cells used for chimera injection; H, heterozgous Cftrtm2Hgu/+ offspring; 1/B, 129/C57 Bl/6 offspring; M, λHindIII molecular weight marker. Login to comment
53 (E) PCR genotyping of G480C mice. Heterozygote Cftrtm2Hgu/+ mice were intercrossed and litters genotyped by PCR and subsequent NsiI digestion. Login to comment
55 wild-type band from the G480C-containing band, which can be digested with the enzyme (Fig. 1E). Login to comment
56 G480C mutant mice express the mutant allele at wild-type levels Both male and female mice heterozygous for the G480C allele were included in the study and a range of tissues investigated. Login to comment
60 G480C products were distinguished from wild-type by the presence of the novel NsiI restriction site polymorphism engineered adjacent to the missense change. Login to comment
62 These results indicate that the modified allele was expressed at the same level as the wild-type allele and therefore the presence of the G480C mutation has no effect on the level of expression. Login to comment
63 G480C CFTR is incompletely processed Analysis of CFTR processing in isolated jejunal enterocytes of wild-type mice by western blotting demonstrated a normal pattern of CFTR isoforms with the core-glycosylated isoform of CFTR (Fig. 3, band B) in the ER, and the mature, fully-glycosylated isoform (Fig. 3, band C) in the plasma membrane. Login to comment
65 In contrast, intestinal epithelium from homozygous G480C mice showed a normal intensity of the B band of CFTR in the crude jejunal membrane fraction (Fig. 3, lane 2), but a strongly reduced intensity of the C band [measured as 8% (±2), n = 4, residual CFTR compared to wild-type as determined by dilution-calibrated scanning of the bioluminescence] in the BBMV (Fig. 3, lanes 2 and 4). Login to comment
66 This outcome clearly demonstrates that the G480C CFTR mutant protein is retained in the ER of the enterocytes in vivo and that only a very small fraction is able to escape the quality control mechanism in the ER and reach the cell surface. Login to comment
69 Expression analysis of the Cftr G480C allele. Login to comment
70 Real-time quantitative RT-PCR expression analysis of the G480C allele was performed. Login to comment
75 Quantification of expression of G480C allele Results from ileum, jejunum and testis show no evidence of an allele bias, only small and inconsistent fluctuations around a 1:1 ratio. Login to comment
77 Tissue Mouse Wild-type (%) G480C (%) Ileum 1 (rp1) 47.13 52.68 1 (rp2) 44.55 55.45 Jejunum 1 47.56 52.44 2 52.13 47.17 Lung 1 20.20 79.80 2 55.20 44.80 Testis 3 (rp1) 56.77 43.23 3 (rp2) 56.65 43.35 Figure 3. Login to comment
78 Western blot analysis of CFTR processing in wild-type and G480C Cftr mice. Login to comment
79 Abnormal processing of G480C CFTR in mouse jejunum. Login to comment
80 Crude epithelial membranes (lanes 1 and 2) and BBMV (lanes 3 and 4) isolated from wild-type (CFTR+/+; lanes 1 and 3) or homozygous G480C mutant mice (lanes 2 and 4) were subjected to western blot analysis as described in Materials and Methods. Login to comment
86 In contrast, CFTR expression in crypts and villi from homozygous G480C mutant mice remained below the detection level of the immunocytochemical technique (Fig. 4B). Login to comment
87 This finding confirms the results of the western blotting shown in Figure 3 and is in line with the concept of a processing defect affecting the maturation of G480C CFTR in both the crypt and villus compartments. Login to comment
88 Phenotype of the CF mutant mice homozygous for the G480C mutation Figure 5 demonstrates that genotypes of the litters produced from matings between G480C heterozygous mice did not deviate from the expected Mendelian ratio of wild-type:heterozygotes:homozygotes of 1:2:1, and no reduction in the number of homozygotes was observed. Login to comment
90 Furthermore, homozygous G480C mice did not show any increased mortality over wild-type animals (pre-or post-weaning) over an 18 month period. Login to comment
92 Histological analysis of intestinal sections demonstrated focal hypertrophy of goblet cells in the G480C homozygous mutant mice. Login to comment
93 Sections from the G480C mutants could easily be distinguished from wild-type by this criterion alone (Fig. 4). Login to comment
98 However, the incisor teeth of the G480C mutant mice were not abnormally white (data not shown). Login to comment
99 Electrophysiological characteristics of G480C CFTR mice The reduced chloride permeability of the epithelium due to CFTR dysfunction, causes typical abnormalities in the ion transport of different epithelia in both CF individuals and Cftr Figure 4. Login to comment
100 Immunohistological analysis of G480C Cftr expression. Login to comment
101 Immunocytochemical staining of CFTR in the jejunum from wild-type mice (A) and homozygous G480C mutant mice (B). Login to comment
103 Crypts and the lower and mid-portion of the villi show intense staining of the apical border of the epithelial cells in wild-type, but not in G480C mouse intestine. Login to comment
105 Similar differences in the CFTR staining pattern were found in four couples of wild-type and G480C mutant mice. Login to comment
108 The G480C CF mice do not suffer from the intestinal blockage (the first signs of which are located in the caecum) that is seen in mice with a complete disruption of Cftr expression, so we examined the electrophysiological profile of these animals in the intestine. Login to comment
109 In the caecum, Ussing chamber measurements revealed that the initial baseline Isc (short circuit current) was significantly (P = 0.0001) reduced in the G480C homozygous mutants compared to controls (Fig. 6A). Login to comment
122 The response to a low chloride gradient was significantly (P = 0.0001) reduced in the G480C mutant animals, in contrast to the normal response reported in the Cftrtm1Eur ∆F508 mouse. Login to comment
123 DISCUSSION The mutant mice we present here mimic human CF individuals with the 'severe` G480C mutation. Login to comment
124 The G480C mutant protein was detected in a pancreatic insufficient African-American CF patient (6). Login to comment
126 This suggested that the G480C protein was similar to the ∆F508 protein and subject to defective intracellular Figure 5. Login to comment
127 G480C mice show good survival and no weight reduction. Login to comment
133 Bioelectric characteristics of (A) caecum, (B) jejunum and (C) nose of wild-type (black bars) and G480C Cftrtm2Hgu homozygous mutant mice (white bars). Login to comment
136 Numbers of animals used, jejunum and caecum baselines and forskolin responses: G480C 12, littermate controls 11, carbachol responses; G480C 6, littermate controls 7; nose baseline: G480C 13, controls 45, nose low chloride: G480C 16, control 38. processing. Login to comment
137 We demonstrate that when replicated in the mouse, the G480C mutant CFTR is mislocalized and the defect in chloride ion transport characteristic of CF varies between tissues and is present in the nose and jejunum but absent from the caecum with no evidence of fatal gut blockage. Login to comment
138 G480C mutant mice express normal levels of the mutant allele The 'hit and run` procedure used to generate these mice results in the only genomic alteration being at the site of the mutation. Login to comment
147 In contrast to the ∆F508 mice generated by replacement gene targeting, the Cftrtm1Eu ∆F508 'hit and run` mice and the Cftrtm2Hgu G480C 'hit and run` mice generated here both express normal levels of the mutant allele. Login to comment
148 G480C mutant protein is mislocalized The majority of G480C CFTR when subjected to western blot analysis is clearly mislocalized in vivo in the mouse intestine. Login to comment
150 This outcome clearly suggests that the majority of G480C CFTR mutant protein is retained in the ER of the enterocytes in vivo but that a significant fraction is able to escape the quality control mechanism in the ER and travel to the cell surface. Login to comment
152 This suggests that the G480C processing defect in the intestine is slightly less severe than that of the ∆F508 mutant in vivo. Login to comment
153 It should be noted that although 8% of normal levels of mature G480C was detectable in western blot analysis of BBMV, only cytoplasmically localized protein could be detected by immunohistochemistry. Login to comment
154 The phenotype of the Cftrtm2Hgu G480C mutant mice is mild The Cftrtm2Hgu G480C mutant mice do not demonstrate a phenotype of death from gut blockage and unlike the ∆F508 Cftrtm1Eur mice do not even display any evidence of growth retardation at weaning. Login to comment
155 The histology of the G480C intestine is not severely abnormal unlike the Cftrtm1Unc 'null` mice, which display extensive goblet cell hyperproliferation, increased mucus accumulation and luminal obstruction. Login to comment
157 The G480C mice (Fig. 4), also do not have any gross abnormalities but do display a mild focal hypertrophy of goblet cells comparable to the data reported for the ∆F508 Cftrtm1Eur homozygotes. Login to comment
158 The classic CF chloride transport defect is not present in the caecum and may account for the lack of intestinal blockage The G480C mutant mice do not show a defect in their forskolin response in the caecum, although baseline and carbachol response are altered compared to wild-type. Login to comment
159 The ∆F508 'hit and run` mutant mice, in contrast to the G480C mice, have a significant but markedly reduced (by 85%) forskolin-activated chloride ion conductance in the caecum compared to wild-type (13). Login to comment
162 Variation between the bioelectric phenotypes of ∆F508 and G480C 'hit and run` mutant mice could be explained by the effect of modifier genes of residual chloride secretion present in the genetic backgrounds on which the mutations have been bred. Login to comment
165 Finally, the G480C mice show 100% survival on a mixed 129/C57Bl/6J background (the same as that reported for the Cftrtm1Eur mice with 100% survival) and this does not alter after four backcrosses onto the C57Bl/6J background. Login to comment
167 It is probable that the normal forskolin response in the G480C mice compared to the abnormal response in Cftrtm1Eur ∆F508 mice is due to slightly more G480C (8% versus 3%) being correctly processed and reaching the apical membrane. Login to comment
168 However, the results from Xenopus oocyte experiments using human CFTR mRNA, strongly suggested that this observed difference between the G480C and ∆F508 response to forskolin was consistent with a trafficking/processing defect in G480C CFTR, and an additional conductance defect in ∆F508 CFTR (6). Login to comment
171 One possible explanation is that the G480C and ∆F508 mouse phenotypes appear to be different to 'null` mice because of differences in human/mouse physiology and gut architecture, and the mouse is more sensitive to small increases in CFTR function. Login to comment
172 Electrophysiological phenotype of the murine G480C mutant protein varies between tissues An unexpected finding was the organ-specific differences in CFTR-related electrophysiology in the mutant mice. Login to comment
181 This must reflect either tissue-specific alterations in the level of mature G480C CFTR with organ-specific subtle translational/post-translational differences, or compensatory pathways altering the bioelectric phenotype. Login to comment
183 The Cftrtm2Hgu G480C mutant mouse is a valuable tool for therapy testing Both the defects in sodium absorption and in chloride secretion are evident in the nose of the G480C mutant mouse and this is widely held to be the mouse tissue that mimics the human respiratory tract phenotype most closely (25). Login to comment
187 The fact that this G480C mutant mouse combines a mistrafficked CFTR mutation (similar to the ∆F508 CFTR) with normal survival means that it is an excellent in vivo model for testing drugs aimed at mutant CFTR relocation strategies. Login to comment
188 In conclusion, the introduction of the G480C mutation into the mouse Cftr gene, using the 'hit and run` technique mimics the human allele with normal levels of Cftr mRNA production. Login to comment
189 This has allowed us to demonstrate that the majority of the G480C mutant protein is mislocalized, but a low level of mature CFTR is detectable by immunoblot. Login to comment
191 The G480C homozygous mutant protein has different ion transport effects in different organs with pronounced effects on the baseline in the nose and the caecum. Login to comment
193 Reduced stimulation of chloride secretion has been found in the nose and the jejunum but a normal response was found in the caecum and this is most likely responsible for the lack of fatal intestinal blockage and the normal weight of the G480C mutant mice. Login to comment
195 Screening of litters for transmission of the G480C allele was performed by PCR using 25 base pair primers used to amplify exon 10 from positions 1530 to 1720 in the Cftr gene, described previously by Dickinson et al. (26), followed by NsiI digestion. Login to comment
196 Real-time RT-PCR analysis Cftrtm2Hgu/+ heterozygous G480C mice were killed by CO2 asphyxiation. Login to comment
218 Western blot analysis Wild-type mice and littermate mice (backcrossed for four generations onto the C57Bl/6 strain background) carrying the G480C mutation were anaesthesized with a hypnorm/diazepam mixture. Login to comment
233 Immunocytochemical analysis Wild-type mice and littermate mice carrying the G480C mutation were killed by cervical dislocation, the intestine was dissected and the jejunum was rinsed with ice-cold saline and fixed in 3% (w/v) paraformaldehyde for 16 h, prior to standard paraffin embedding. Login to comment
241 Electrophysiological analysis G480C homozygous animals were assessed in vivo (nose) and in vitro (jejunum, caecum) and compared with littermate controls. Login to comment

[hide] Cystic fibrosis: a worldwide analysis of CFTR muta... Hum Mutat. 2002 Jun;19(6):575-606. Bobadilla JL, Macek M Jr, Fine JP, Farrell PM
Cystic fibrosis: a worldwide analysis of CFTR mutations--correlation with incidence data and application to screening.
Hum Mutat. 2002 Jun;19(6):575-606., [PMID:12007216]

Abstract [show]
Although there have been numerous reports from around the world of mutations in the gene of chromosome 7 known as CFTR (cystic fibrosis transmembrane conductance regulator), little attention has been given to integrating these mutant alleles into a global understanding of the population molecular genetics associated with cystic fibrosis (CF). We determined the distribution of CFTR mutations in as many regions throughout the world as possible in an effort designed to: 1) increase our understanding of ancestry-genotype relationships, 2) compare mutational arrays with disease incidence, and 3) gain insight for decisions regarding screening program enhancement through CFTR multi-mutational analyses. Information on all mutations that have been published since the identification and cloning of the CFTR gene's most common allele, DeltaF508 (or F508del), was reviewed and integrated into a centralized database. The data were then sorted and regional CFTR arrays were determined using mutations that appeared in a given region with a frequency of 0.5% or greater. Final analyses were based on 72,431 CF chromosomes, using data compiled from over 100 original papers, and over 80 regions from around the world, including all nations where CF has been studied using analytical molecular genetics. Initial results confirmed wide mutational heterogeneity throughout the world; however, characterization of the most common mutations across most populations was possible. We also examined CF incidence, DeltaF508 frequency, and regional mutational heterogeneity in a subset of populations. Data for these analyses were filtered for reliability and methodological strength before being incorporated into the final analysis. Statistical assessment of these variables revealed that there is a significant positive correlation between DeltaF508 frequency and the CF incidence levels of regional populations. Regional analyses were also performed to search for trends in the distribution of CFTR mutations across migrant and related populations; this led to clarification of ancestry-genotype patterns that can be used to design CFTR multi-mutation panels for CF screening programs. From comprehensive assessment of these data, we offer recommendations that multiple CFTR alleles should eventually be included to increase the sensitivity of newborn screening programs employing two-tier testing with trypsinogen and DNA analysis.

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113 Mexico ∆F508 (41.6%) G551S (0.5%) 75.5 57.0 35 374/194 Orozco et al.[1993]; Villalobos- G542X (5.6%) 1078delT (0.5%) Torres et al. [1997]; Liang et al. ∆I507 (2.5%) Y1092X (0.5%) [1998]; Orozco et al. [2000] S549N (1.9%) R117H (0.5%) N1303K (1.7%) G85E (0.5%) R75X (1.5%) 1716G→A (0.5%) 406-1G→A (1.5%) W1204X (0.5%) I148T (1.5%) W1098C (0.5%) 3849+10KbC→T (1.5%) 846delT (0.5%) 621+1G→T (1.2%) P750L (0.5%) 2055del9→A (1.0%) V754M (0.5%) 935delA (1.0%) R75Q (0.5%) I506T (1.0) W1096X (0.5%) 3199del6 (1.0%) L558S (0.5%) 2183AA→G (1.0%) 4160insGGGG (0.5%) G551D (0.5%) 297-1G→A (0.5%) R553X (0.5%) H199Y (0.5%) 1924del7 (0.5%) United States ∆F508 (68.6%) R553X (0.9%) 79.7 63.5 10 25048 Cystic Fibrosis Foundation (total) G542X (2.4%) 621+1G→T (0.9%) [1998] G551D (2.1%) 1717-1G→A (0.7%) W1282X (1.4%) 3849+10KbC→T (0.7%) N1303K (1.3%) R117H (0.7%) United States ∆F508 (48.0%) S1255X (1.4%) 77.3 59.8 16 160/148 Carles et al. [1996]; Macek et al. (African 3120+1G→A (12.2%) 444delA (0.7%) [1997]; Dörk et al. [1998]; American) 2307insA (2.0%) R334W (0.7%) Friedman et al. [1998] A559T (2.0%) ∆I507 (0.7%) R553X (2.0%) 1717-1G→A (0.7%) ∆F311 (2.0%) G542X (0.7%) G480C (1.4%) S549N (0.7%) 405+3A→C (1.4%) G551D (0.7%) United States 1) L1093P - - 1 2 Yee et al. [2000] (Cherokee) United States Non-French: French: Non- Non- Non- Non- Bayleran et al. [1996] (Maine) ∆F508 (82.0%) ∆F508 (58%) French: French: French: French: G542X (2.6%) 711+1G→T (8.3%) 95.3 90.8 11 191 G551D (2.6%) I148T (4.2%) French: French: French: French: N1303K (2.1%) A455E (4.2%) 80.3 64.5 8 72 R560T (1.0%) 1717-1G→A (1.4%) Total: 621+1G→T (1.0%) G85E (1.4%) 263 711+1G→T (1.0%) 621+1G→T (1.4%) R117H (1.0%) Y1092X (1.4%) 1717-1G→A (1.0%) G85E (0.5%) W1282X (0.5%) TABLE 1. Continued. Estimated Projected detection of Number of Number of Country/ allele two CFTR mutations chromosomes Region Mutation array detectiona mutationsb includedc (max/min)d Reference WORLDWIDEANALYSISOFCFTRMUTATIONS589 United States ∆F508 (46.0%) R334W (1.6%) 58.5 34.2 7 129 Grebe et al. [1994] (SW Hispanic) G542X (5.4%) W1282X (0.8%) 3849+10KbC→T (2.3%) R553X (0.8%) R1162X (1.6%) United States 1) R1162X - - 3 17 Mercier et al. [1992] (SW Native 2) D648V American) 3) G542X United States 1) R1162X 3) G542X - - 4 16 Mercier et al. [1994] (Zuni Pueblo) 2) 3849+10KbC®T 4) D648V Venezuela ∆F508 (29.6%) G542X (3.7%) 33.3 11.1 2 54 Restrepo et al. [2000] Other Regions Australia ∆F508 (76.9%) 621+1G→T (1.1%) 88.7 78.7 8 761/464 CFGAC [1994] G551D (4.5%) N1303K (0.9%) G542X (2.8%) W1282X (0.6%) R553X (1.3%) R117H (0.6%) East Asia 1) 1898+1G®T 2) 1898+5G®T - - 2 28 Suwanjutha et al. [1998] Hutterite 1) M1101K (69.0%) 2) DF508 (31.0%) - - 2 32 Zielenski et al. [1993] Brethren New Zealand ∆F508 (78.0%) N1303K (1.9%) 87.4 76.4 5 636 CFGAC [1994] G551D (4.4%) 621+1G→T (1.1%) G542X (2.0%) *This table presents the mutation panels for all regions investigated in this study. Login to comment
213 Ideal Recommended CFTR Mutation Screening Panel for 2001 Neonatal Screening in the USA* Location Estimated Mutation in CFTRa percentageb Reason for inclusion DF508 Exon 10 68.6% CFF registry, >1%, Pan-European G542X Exon 11 2.4% CFF registry, >1%, Mediterranean G551D Exon 11 2.1% CFF registry, >1%, Celtic W1282X Exon 20 1.4% CFF registry, >1%, Ashkenazi Jew N1303K Exon 21 1.3% CFF registry, >1%, Mediterranean R553X Exon 11 0.9% CFF registry, >0.5%, Hispanic 621+1G®T Intron 4 0.9% CFF registry, >0.5%, multi-ethnic 1717-1G®A Intron 10 0.7% CFF registry, >0.5%, Italian 3849+10KbC®T Intron 19 0.7% CFF registry, >0.5%, Hispanic R117Hc Exon 4 0.7% CFF registry, >0.5% 1898+1G→T Intron 12 0.4% CFF registry, >0.1%, East Asian DI507 Exon 10 0.3% CFF registry, >0.1%, Hispanic 2789+5G®A Intron 14b 0.3% CFF registry, >0.1% G85E Exon 3 0.3% CFF registry, >0.1% R347P Exon 7 0.2% CFF registry, >0.1% R334W Exon 7 0.2% CFF registry, >0.1%, multi-ethnic R1162X Exon 19 0.2% CFF registry, >0.1%, multi-ethnic R560T Exon 11 0.2% CFF registry, >0.1% 3659delC Exon 19 0.2% CFF registry, >0.1% A455E Exon 9 0.2% CFF registry, >0.1% 2184delA Exon 13 0.1% CFF registry, >0.1% S549N Exon 11 0.1% CFF registry, >0.1%, multi-ethnic 711+1G®T Intron 5 0.1% CFF registry, >0.1% R75X Exon 3 0.2% Hispanic 406-1G→A Intron 3 0.2% Hispanic I148T Exon 4 0.2% Hispanic, French 2055del9→A Exon 13 0.1% Hispanic 935delA Exon 6b 0.1% Hispanic I506T Exon 10 0.1% Hispanic 3199del6 Exon 17a 0.1% Hispanic 2183AA→G Exon 13 0.1% Hispanic 3120+1G®A Intron 16 1.5% African American, Arabian 2307insA Exon 13 0.2% African American A559T Exon 11 0.2% African American ∆F311 Exon 7 0.2% African American G480C Exon 10 0.2% African American 405+3A→C Intron 3 0.2% African American S1255X Exon 20 0.2% African American L1093P Exon 17b Undetermined Native American D648V Exon 13 Undetermined Native American I1234V Exon 19 Undetermined Arabian linkage S549R Exon 11 Undetermined Arabian linkage 1898+5G→T Intron 12 Undetermined East Asian linkage CFTRdele2,3 Exons 2,3 Undetermined Eastern European linkage (Slavic) Y1092X Exon 17b Undetermined French linkage 394delTT Exon 3 Undetermined Nordic linkage Y569D Exon 12 Undetermined Pakistani linkage 3905insT Exon 20 Undetermined Swiss linkage (also: Amish, Acadian, Mennonite) 1898+1G®A Intron 12 Undetermined Welsh linkage M1101k Exon 17b Undetermined Hutterite ancestry *This table presents the top 50 mutations in the USA based on the Cystic Fibrosis Foundation CF Registry data from 1997 [Cystic Fibrosis Foundation, 1998], and data generated during our investigation. Login to comment

[hide] Development and evaluation of a PCR-based, line pr... Clin Chem. 2002 Jul;48(7):1121-3. Wang X, Myers A, Saiki RK, Cutting GR
Development and evaluation of a PCR-based, line probe assay for the detection of 58 alleles in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.
Clin Chem. 2002 Jul;48(7):1121-3., [PMID:12089190]

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68 Amplicon Size, bp Mutations (polymorphisms) Exon 13 598 2307 insA Intron 8, exon 09 548 A455E, 5T (7/9 T polymorphism) Exon 10 482 G480C, ⌬I507, ⌬F508 (F508C, I507V, I506V polymorphisms) Intron 10, exon 11 433 1717-1G3A, G542X, G551D, R553X, A559T, R560T Exon 19 420 R1162X, 3659delC Exon 21 397 N1303K Exon 20 359 S1255X, W1282X Exon 07 328 1078delT, R334W, R347P Exon 04, intron 4 288 R117H, 621ϩ1G3T Intron 14b 248 2789ϩ5G3A Intron 19 237 3849ϩ10kbC3T Exon 03 210 G85E, 405ϩ3A3C Intron 5 166 711ϩ1G3T Intron 16 139 3120ϩ1G3A Clinical Chemistry 48, No. Login to comment
80 The signal intensities of the wild-type alleles for A455E, G480C, I507/F508, and 2307insA probes were decreased when 12.5 ng of DNA was used, but could still be distinguished from background even at 6.25 ng of DNA. Login to comment
88 The genotypes of each sample are as follows: lane 1, ϩ/ϩ (ϩ is the wild type); lane 2, 5T, R117H/3659delC; lane 3, G542X/ϩ; lane 4, I506V/ϩ; lane 5, I507V/ϩ; lane 6, F508C/⌬F508; lane 7, G85E/⌬F508; lane 8, 405ϩ3A3C/3120ϩ1G3C; lane 9, R117H/ϩ; lane 10, 621ϩ1G3T/⌬F508; lane 11, 711ϩ1G3T/⌬F508; lane 12, 1078delT/ϩ; lane 13, R334W/⌬F508; lane 14, R347P/⌬F508; lane 15, A455E/ϩ; lane 16, G480C/⌬F508; lane 17, ⌬I507/ϩ; lane 18, ⌬F508/ϩ; lane 19, 1717-1G3A/ϩ; lane 20, G542X/ϩ; lane 21, G551D/⌬F508; lane 22, R553X/ϩ; lane 23, R560T/⌬F508; lane 24, G551D/A559T; lane 25, 2307insA/ϩ; lane 26, 2789ϩ5G3A/⌬F508; lane 27, 3120ϩ1G3A/⌬F508; lane 28, R1162X/R1162X; lane 29, 3659delC/⌬F508; lane 30, 3849ϩ10kbC3T/⌬F508; lane 31, S1255X/⌬F508; lane 32, W1282X/G542X; lane 33, N1303K/ϩ. Login to comment

[hide] Analysis by mass spectrometry of 100 cystic fibros... Hum Reprod. 2002 Aug;17(8):2066-72. Wang Z, Milunsky J, Yamin M, Maher T, Oates R, Milunsky A
Analysis by mass spectrometry of 100 cystic fibrosis gene mutations in 92 patients with congenital bilateral absence of the vas deferens.
Hum Reprod. 2002 Aug;17(8):2066-72., [PMID:12151438]

Abstract [show]
BACKGROUND: Limited mutation analysis for congenital bilateral absence of the vas deferens (CBAVD) has revealed only a minority of men in whom two distinct mutations were detected. We aimed to determine whether a more extensive mutation analysis would be of benefit in genetic counselling and prenatal diagnosis. METHODS: We studied a cohort of 92 men with CBAVD using mass spectrometry and primer oligonucleotide base extension to analyse an approximately hierarchical set of the most common 100 CF mutations. RESULTS: Analysis of 100 CF mutations identified 33/92 (35.9%) patients with two mutations and 29/92 (31.5%) with one mutation, compound heterozygosity accounting for 94% (31/33) of those with two mutations. This panel detected 12.0% more CBAVD men with at least one mutation and identified a second mutation in >50% of those considered to be heterozygotes under the two routine 25 mutation panel analyses. CONCLUSION: Compound heterozygosity of severe/mild mutations accounted for the vast majority of the CBAVD patients with two mutations, and underscores the value of a more extensive CF mutation panel for men with CBAVD. The CF100 panel enables higher carrier detection rates especially for men with CBAVD, their partners, partners of known CF carriers, and those with 'mild' CF with rarer mutations.

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20 Given the frequency of CF mutations, especially in the Caucasian population ( in 25), and the common request by CBAVD men to sire their own offspring by using surgical Table I. The 100 most common cystic fibrosis mutations listed by exon Mutationa Exonb Frequency (%)c G85E 3 0.1 394delTT 3 Swedish E60X 3 Belgium R75X 3 405ϩ1G→A Int 3 R117H 4 0.30 Y122X 4 French 457TAT→G 4 Austria I148T 4 Canada (French Canadian) 574delA 4 444delA 4 R117L 4 621ϩ1G→T Int 4 0.72 711ϩ1G→T Int 5 Ͼ0.1 712-1G→T Int 5 711ϩ5G→A Int 5 Italy (Caucasian) L206W 6a R347P 7 0.24 1078delT 7 Ͼ0.1 R334W 7 Ͼ0.1 1154InsTC 7 T338I 7 Italy R347H 7 Turkey Q359K/T360K 7 Israel (Georgian Jews) I336K 7 R352Q 7 G330X 7 S364P 7 A455E 9 0.20 I507 10 0.21 F508 10 66.02 1609delCA 10 Spain (Caucasian) V520F 10 Q493X 10 C524X 10 G480C 10 Q493R 10 1717-1G→A Int 10 0.58 R553X 11 0.73 G551D 11 1.64 G542X 11 2.42 R560T 11 Ͼ0.1 S549N 11 Q552X 11 Italy S549I 11 Israel (Arabs) A559T 11 African American R553G 11 R560K 11 1812-1G→A Int 11 A561E 12 E585X 12 Y563D 12 Y563N 12 1898ϩ1G→A Int 12 0.22 1898ϩ1G→C Int 12 2183AA→G 13 Italian 2184delA 13 Ͻ0.1 K710X 13 2143delT 13 Moscow (Russian) 2184InsA 13 1949del84 13 Spain (Spanish) 2176InsC 13 2043delG 13 2307insA 13 2789ϩ5G→A Int 14b Ͼ0.1 2869insG 15 S945L 15 Q890X 15 3120G→A 16 2067 Table I. continued Mutationa Exonb Frequency (%)c 3120ϩ1G→A Int 16 African American 3272-26A→G Int 17a R1066C 17b Portugal (Portugese) L1077P 17b R1070Q 17b Bulgarian W1089X 17b M1101K 17b Canada (Hutterite) R1070P 17b R1162X 19 0.29 3659delC 19 Ͼ0.1 3849G→A 19 3662delA 19 3791delC 19 3821delT 19 Russian Q1238X 19 S1235R 19 France, South S1196X 19 K1177R 19 3849ϩ10kbC→T Int 19 0.24 3849ϩ4A→G Int 19 W1282X 20 1.22 S1251N 20 Dutch, Belgian 3905insT 20 Swiss, Acadian, Amish G1244E 20 R1283M 20 Welsh W1282R 20 D1270N 20 S1255X 20 African American 4005ϩ1G→A Int 20 N1303K 21 1.34 W1316X 21 aMutations were chosen according to their frequencies (Cystic Fibrosis Genetic Analysis Consortium, 1994; Zielenski and Tsui, 1995; Estivill et al., 1997). Login to comment

[hide] Standards and guidelines for CFTR mutation testing... Genet Med. 2002 Sep-Oct;4(5):379-91. Richards CS, Bradley LA, Amos J, Allitto B, Grody WW, Maddalena A, McGinnis MJ, Prior TW, Popovich BW, Watson MS, Palomaki GE
Standards and guidelines for CFTR mutation testing.
Genet Med. 2002 Sep-Oct;4(5):379-91., [PMID:12394352]

Abstract [show]
One mission of the ACMG Laboratory Quality Assurance (QA) Committee is to develop standards and guidelines for clinical genetics laboratories, including cytogenetics, biochemical, and molecular genetics specialties. This document was developed under the auspices of the Molecular Subcommittee of the Laboratory QA Committee by the Cystic Fibrosis (CF) Working Group. It was placed on the "fast track" to address the preanalytical, analytical, and postanalytical quality assurance practices of laboratories currently providing testing for CF. Due to the anticipated impact of the ACMG recommendation statement endorsing carrier testing of reproductive couples, it was viewed that CF testing would increase in volume and that the number of laboratories offering CF testing would also likely increase. Therefore, this document was drafted with the premise of providing useful information gained by experienced laboratory directors who have provided such testing for many years. In many instances, "tips" are given. However, these guidelines are not to be interpreted as restrictive or the only approach but to provide a helpful guide. Certainly, appropriately trained and credentialed laboratory directors have flexibility to utilize various testing platforms and design testing strategies with considerable latitude. We felt that it was essential to include technique-specific guidelines of several current technologies commonly used in laboratories providing CF testing, since three of the four technologies discussed are available commercially and are widely utilized. We take the view that these technologies will change, and thus this document will change with future review.

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52 CF 2.8.2 Mutations specific for the African-American population have been described12 and include 3120 ϩ 1GϾA, A559T, G330X, 2307insA, ⌬F311, and G480C. Login to comment

[hide] Structure of nucleotide-binding domain 1 of the cy... EMBO J. 2004 Jan 28;23(2):282-93. Epub 2003 Dec 18. Lewis HA, Buchanan SG, Burley SK, Conners K, Dickey M, Dorwart M, Fowler R, Gao X, Guggino WB, Hendrickson WA, Hunt JF, Kearins MC, Lorimer D, Maloney PC, Post KW, Rajashankar KR, Rutter ME, Sauder JM, Shriver S, Thibodeau PH, Thomas PJ, Zhang M, Zhao X, Emtage S
Structure of nucleotide-binding domain 1 of the cystic fibrosis transmembrane conductance regulator.
EMBO J. 2004 Jan 28;23(2):282-93. Epub 2003 Dec 18., 2004-01-28 [PMID:14685259]

Abstract [show]
Cystic fibrosis transmembrane conductance regulator (CFTR) is an ATP-binding cassette (ABC) transporter that functions as a chloride channel. Nucleotide-binding domain 1 (NBD1), one of two ABC domains in CFTR, also contains sites for the predominant CF-causing mutation and, potentially, for regulatory phosphorylation. We have determined crystal structures for mouse NBD1 in unliganded, ADP- and ATP-bound states, with and without phosphorylation. This NBD1 differs from typical ABC domains in having added regulatory segments, a foreshortened subdomain interconnection, and an unusual nucleotide conformation. Moreover, isolated NBD1 has undetectable ATPase activity and its structure is essentially the same independent of ligand state. Phe508, which is commonly deleted in CF, is exposed at a putative NBD1-transmembrane interface. Our results are consistent with a CFTR mechanism, whereby channel gating occurs through ATP binding in an NBD1-NBD2 nucleotide sandwich that forms upon displacement of NBD1 regulatory segments.

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216 CF mutations in NBD1 The majority of sites of CF-causing missense mutations occur in NBD1, primarily in its a-subdomain, and the locations in the mNBD1 structure of the most common of these (A455E, G480C, I506T, DI507, DF508, S549N, S549R, G551D, A559T, R560T, Y569D, and D648V; Bobadilla et al, 2002) are shown in Figure 3D. Login to comment

[hide] Novel CFTR mutations in black cystic fibrosis pati... Clin Genet. 2004 Apr;65(4):284-7. Feuillet-Fieux MN, Ferrec M, Gigarel N, Thuillier L, Sermet I, Steffann J, Lenoir G, Bonnefont JP
Novel CFTR mutations in black cystic fibrosis patients.
Clin Genet. 2004 Apr;65(4):284-7., [PMID:15025720]

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Cystic fibrosis (CF) is considered as a rare disease in black Africans. In fact, this disease is likely to be underestimated since clinical features consistent with CF diagnosis are often ascribed to environmental factors such as malnutrition. Very little is known about CFTR mutations in affected patients from Central Africa. We report here four novel mutations, i.e., IVS2 + 28 (intron 2), 459T > A (exon 4), EX17a_EX18del (exons 17-18), and IVS22 + IG > A (intron 22), in such patients. An update of CFTR mutations reported in black patients from various ethnies is included. These data might be helpful for genetic counselling regarding CF in black patients.

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70 Cystic fibrosis (CF) mutations reported in black patients African-Americans South Africans Central Africans Guianese Mutation n/N Reference Mutation n/N Reference Mutation n/N Reference Mutation 3120þ1G>A 18/148 (7) 3120þ1G>A 11/24 (4) 3120þ1G>A 1/2 (1) 14/112 (1) 2/10 4/6 (2) (1) W19C (7) À94G>T 1/24 (4) 3600þ11.5kbC>G 4/4 (13) IVS22þ1G>A* 405þ3A>C 2/148 (7) 2183delAA 1/24 (4) Y109X* 444delA 1/148 (7, 19) 3196del54 1/24 (4) EX17a-EX18 del* 621G>A (7) G1249E 1/24 (4) IVS2þ28A>G* 1002-3T>G (7) 1/6 (1) 1119delA (7) D1270N 2/10 (2) G330X (7) F311del 1/24 (20) S364P (7) 1342-2delAG (7) 1504delG (7) G480C 2/148 (6, 7) R553X 3/148 (7) A559T 3/148 (7) Y563D (7) I618T (7) R764X (7) 2307insA 3/148 (7, 21) 2734delG/insAT (7) 3662delA (22) 3791delC (7) S1255X 2/148 (7, 23) R1283S (24) W1316X (23) n, number of CF chromosomes with a given mutation; N, total number of CF chromosomes tested. Login to comment

[hide] Instability of the insertional mutation in CftrTgH... BMC Genet. 2004 Apr 21;5:6. Charizopoulou N, Jansen S, Dorsch M, Stanke F, Dorin JR, Hedrich HJ, Tummler B
Instability of the insertional mutation in CftrTgH(neoim)Hgu cystic fibrosis mouse model.
BMC Genet. 2004 Apr 21;5:6., 2004-04-21 [PMID:15102331]

Abstract [show]
BACKGROUND: A major boost to the cystic fibrosis disease research was given by the generation of various mouse models using gene targeting in embryonal stem cells. Moreover, the introduction of the same mutation on different inbred strains generating congenic strains facilitated the search for modifier genes. From the original CftrTgH(neoim)Hgu CF mouse model we have generated using strict brother x sister mating two inbred CftrTgH(neoim)Hgu mouse lines (CF/1 and CF/3). Thereafter, the insertional mutation was introgressed from CF/3 into three inbred backgrounds (C57BL/6, BALB/c, DBA/2J) generating congenic animals. In every backcross cycle germline transmission of the insertional mutation was monitored by direct probing the insertion via Southern RFLP. In order to bypass this time consuming procedure we devised an alternative PCR based protocol whereby mouse strains are differentiated at the Cftr locus by Cftr intragenic microsatellite genotypes that are tightly linked to the disrupted locus. RESULTS: Using this method we were able to identify animals carrying the insertional mutation based upon the differential haplotypic backgrounds of the three inbred strains and the mutant CftrTgH(neoim)Hgu at the Cftr locus. Moreover, this method facilitated the identification of the precise vector excision from the disrupted Cftr locus in two out of 57 typed animals. This reversion to wild type status took place without any loss of sequence revealing the instability of insertional mutations during the production of congenic animals. CONCLUSIONS: We present intragenic microsatellite markers as a tool for fast and efficient identification of the introgressed locus of interest in the recipient strain during congenic animal breeding. Moreover, the same genotyping method allowed the identification of a vector excision event, posing questions on the stability of insertional mutations in mice.

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13 These fall broadly into two different categories; those designed to mimic clinical human mutations such as the F508del [2-4], G551D [5] and G480C [6], and those with a disrupted Cftr gene resulting in either no or reduced production of CFTR. Login to comment

[hide] Bayesian risk assessment for autosomal recessive d... J Med Genet. 2004 May;41(5):e70. Ogino S, Wilson RB, Grody WW
Bayesian risk assessment for autosomal recessive diseases: fetal echogenic bowel with one or no detectable CFTR mutation.
J Med Genet. 2004 May;41(5):e70., [PMID:15121798]

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185 If a relative of parent A or parent B is affected or an obligate carrier, this table can still be applied when neither that relative nor any other family member has been tested. Table 3 Summary of carrier frequencies for cystic fibrosis, overall mutation detection rates by the ACMG 25 mutation panel, and frequencies of major mutations for each major ethnic group (adapted from Richards et al. and Bobadilla et al.)4 18 Ethnic group Cystic fibrosis carrier frequency Overall mutation detection rate by ACMG CFTR 25 mutation panel (%) Frequency DF508 among all disease alleles (%) Other major mutations (%)* Non-Hispanic 1/25 90 70 G542X 2.4 Caucasian G551D 2.1 W1282X 1.4 N1303K 1.3 Ashkenazi Jewish 1/25 97 30 W1282X 48 G542X 9.0 3849+10kbCRT 6.0 N1303K 3.0 1717-1GRA 1.0 African-American 1/65 69 48 3120+1GRA 12 2307insA 2.0 A559T 2.0 R553X 2.0 DF311 2.0 G480C 1.4 405+3ARC 1.4 S1255X 1.4 Hispanic American 1/46 57 46 G542X 5.4 3849+10kbCRT 2.3 R1162X 1.6 R334W 1.6 Asian American 1/90 ? Login to comment

[hide] Population-based newborn screening for genetic dis... Pediatrics. 2004 Jun;113(6):1573-81. Comeau AM, Parad RB, Dorkin HL, Dovey M, Gerstle R, Haver K, Lapey A, O'Sullivan BP, Waltz DA, Zwerdling RG, Eaton RB
Population-based newborn screening for genetic disorders when multiple mutation DNA testing is incorporated: a cystic fibrosis newborn screening model demonstrating increased sensitivity but more carrier detections.
Pediatrics. 2004 Jun;113(6):1573-81., [PMID:15173476]

Abstract [show]
OBJECTIVES: Newborn screening for cystic fibrosis (CF) provides a model to investigate the implications of applying multiple-mutation DNA testing in screening for any disorder in a pediatric population-based setting, where detection of affected infants is desired and identification of unaffected carriers is not. Widely applied 2-tiered CF newborn screening strategies first test for elevated immunoreactive trypsinogen (IRT) with subsequent analysis for a single CFTR mutation (DeltaF508), systematically missing CF-affected infants with any of the >1000 less common or population-specific mutations. Comparison of CF newborn screening algorithms that incorporate single- and multiple-mutation testing may offer insights into strategies that maximize the public health value of screening for CF and other genetic disorders. The objective of this study was to evaluate technical feasibility and practical implications of 2-tiered CF newborn screening that uses testing for multiple mutations (multiple-CFTR-mutation testing). METHODS: We implemented statewide CF newborn screening using a 2-tiered algorithm: all specimens were assayed for IRT; those with elevated IRT then had multiple-CFTR-mutation testing. Infants who screened positive by detection of 1 or 2 mutations or extremely elevated IRT (>99.8%; failsafe protocol) were then referred for definitive diagnosis by sweat testing. We compared the number of sweat-test referrals using single- with multiple-CFTR-mutation testing. Initial physician assessments and diagnostic outcomes of these screened-positive infants and any affected infants missed by the screen were analyzed. We evaluated compliance with our screening and follow-up protocols. All Massachusetts delivery units, the Newborn Screening Program, pediatric health care providers who evaluate and refer screened-positive infants, and the 5 Massachusetts CF Centers and their affiliated genetic services participated. A 4-year cohort of 323 506 infants who were born in Massachusetts between February 1, 1999, and February 1, 2003, and screened for CF at approximately 2 days of age was studied. RESULTS: A total of 110 of 112 CF-affected infants screened (negative predictive value: 99.99%) were detected with IRT/multiple-CFTR-mutation screening; 2 false-negative screens did not show elevated IRT. A total of 107 (97%) of the 110 had 1 or 2 mutations detected by the multiple- CFTR-mutation screen, and 3 had positive screens on the basis of the failsafe protocol. In contrast, had we used single-mutation testing, only 96 (87%) of the 110 would have had 1 or 2 mutations detectable by single-mutation screen, 8 would have had positive screens on the basis of the failsafe protocol, and an additional 6 infants would have had false-negative screens. Among 110 CF-affected screened-positive infants, a likely "genetic diagnosis" was made by the multiple-CFTR-mutation screen in 82 (75%) versus 55 (50%) with DeltaF508 alone. Increased sensitivity from multiple-CFTR-mutation testing yielded 274 (26%) more referrals for sweat testing and carrier identifications than testing with DeltaF508 alone. CONCLUSIONS: Use of multiple-CFTR-mutation testing improved sensitivity and postscreening prediction of CF at the cost of increased referrals and carrier identification.

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80 The 27-mutation panel included all of the 16 except S549N and the following additional mutations: 3120 ϩ 1GϾA, 3659delC, A559T, R1162X, S1255X, 405 ϩ 3AϾC, 711 ϩ 1GϾT, 2789 ϩ 5GϾA, G480C, 2307insA, G85E, and 1078delT. Login to comment

[hide] Preconception and prenatal cystic fibrosis carrier... Genet Med. 2004 May-Jun;6(3):141-4. Monaghan KG, Bluhm D, Phillips M, Feldman GL
Preconception and prenatal cystic fibrosis carrier screening of African Americans reveals unanticipated frequencies for specific mutations.
Genet Med. 2004 May-Jun;6(3):141-4., [PMID:15354332]

Abstract [show]
PURPOSE: It is recommended that cystic fibrosis (CF) carrier screening be made available to African Americans who are either pregnant or planning a pregnancy. We analyzed the carrier and mutant allele frequencies for African Americans undergoing CF carrier screening in our laboratories. METHODS: Between December 2001 and September 2003, we performed carrier screening for 2189 African Americans, testing for at least the 25 recommended mutations. RESULTS: A total of 33 CF carriers were identified. The most common mutations detected were deltaF508, G622D, R117H/7T, and G551D. The G622D allele frequency among African Americans was 0.18%. We did not detect any 3120 + 1G --> A carriers, although 4 were expected (P < 0.05). CONCLUSIONS: When considering only the 25 recommended CF mutations, 1 in 75 African Americans screened in our laboratories were carriers (within the expected range, given a 69% mutation detection rate). The addition of 2 mutations, G622D and Q98R (incidentally identified while screening for ACOG/ACMG mutations), increased the observed carrier frequency to 1 in 66, which is not significantly different from the known African American carrier frequency of 1 in 65. The frequencies of several specific mutations detected were unanticipated, as was the absence of 3120 + 1G --> A carriers. Further studies on African American patients with classic CF are needed to examine the incidence of CF mutations that are not part of the current panel, such as G622D.

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73 In addition to ⌬F508 and 3120ϩ1G3A, which are both included in the current mutation panel, other mutations outside of the ACOG/ACMG panel have been reported in African Americans (405ϩ3A3C, 444delA, ⌬F311, G480C, A559T, 2307insA, 196del54, G1249E, S1255X and D1270N6,7,13,14,15). Login to comment

[hide] CFTR mutation distribution among U.S. Hispanic and... Genet Med. 2004 Sep-Oct;6(5):392-9. Sugarman EA, Rohlfs EM, Silverman LM, Allitto BA
CFTR mutation distribution among U.S. Hispanic and African American individuals: evaluation in cystic fibrosis patient and carrier screening populations.
Genet Med. 2004 Sep-Oct;6(5):392-9., [PMID:15371903]

Abstract [show]
PURPOSE: We reviewed CFTR mutation distribution among Hispanic and African American individuals referred for CF carrier screening and compared mutation frequencies to those derived from CF patient samples. METHODS: Results from CFTR mutation analyses received from January 2001 through September 2003, were analyzed for four populations: Hispanic individuals with a CF diagnosis (n = 159) or carrier screening indication (n = 15,333) and African American individuals with a CF diagnosis (n = 108) or carrier screening indication (n = 8,973). All samples were tested for the same 87 mutation panel. RESULTS: In the Hispanic population, 42 mutations were identified: 30 in the patient population (77.5% detection rate) and 33 among carrier screening referrals. Five mutations not included in the ACMG/ACOG carrier screening panel (3876delA, W1089X, R1066C, S549N, 1949del84) accounted for 7.55% detection in patients and 5.58% among carriers. Among African American referrals, 33 different mutations were identified: 21 in the patient population (74.4% detection) and 23 in the carrier screening population. Together, A559T and 711+5G>A were observed at a detection rate of 3.71% in CF patients and 6.38% in carriers. The mutation distribution seen in both the carrier screening populations reflected an increased frequency of mutations with variable expression such as D1152H, R117H, and L206W. CONCLUSIONS: A detailed analysis of CFTR mutation distribution in the Hispanic and African American patient and carrier screening populations demonstrates that a diverse group of mutations is most appropriate for diagnostic and carrier screening in these populations. To best serve the increasingly diverse U.S. population, ethnic-specific mutations should be included in mutation panels.

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35 87 mutation panel The following mutations were included in the panel: ⌬F508, ⌬F311, ⌬I507, A455E, A559T, C524X, D1152H, D1270N, E60X, G178R, G330X, G480C, G542X, G551D, G85E, G91R, I148T, K710X, L206W, M1101K, N1303K, P574H, Q1238X, Q359K/T360K, Q493X, Q552X, Q890X, R1066C, R1158X, R1162X, R117C, R117H, R1283M, R334W, R347H, R347P, R352Q, R553X, R560T, S1196X, S1251N, S1255X, S364P, S549I, S549N, S549R, T338I, V520F, W1089X, W1282X, Y1092X, Y563D, 1078delT, 1161delC, 1609delCA, 1677delTA, 1717-1GϾA, 1812-1GϾA, 1898ϩ1GϾA, 1898ϩ5GϾT, 1949del84, 2043delG, 2143delT, 2183delAAϾG, 2184delA, 2307insA, 2789ϩ5GϾA, 2869insG, 3120ϩ1GϾA, 3120GϾA, 3659delC, 3662delA, 3791delC, 3821delT, 3849ϩ10kbCϾT, 3849ϩ4AϾG, 3905insT, 394delTT, 405ϩ1GϾA, 405ϩ3AϾC, 444delA, 574delA, 621ϩ1GϾT, 711ϩ1GϾT, 711ϩ5GϾA, 712-1GϾT, 3876delA CFTR mutation analysis Genomic DNA was extracted from peripheral blood lymphocytes, buccal cell swabs, or bloodspots by Qiagen QIAmp 96 DNA Blood Kit. Specimens were tested for 87 mutations by a pooled allele-specific oligonucleotide (ASO) hybridization method as previously described.16,17 Two multiplex chain reactions (PCR) were used to amplify 19 regions of the CFTR gene. Login to comment
87 Five of the twelve mutations identified once are considered to be "African American" mutations (3791delC, G330X, G480C, 444delA, and S1255X).19 African American CF carrier screening population Among the 8,973 African American individuals referred for carrier screening, 23 different mutations were identified among 94 (1/95) carriers (Table 2). Login to comment

[hide] Use of MALDI-TOF mass spectrometry in a 51-mutatio... Genet Med. 2004 Sep-Oct;6(5):426-30. Buyse IM, McCarthy SE, Lurix P, Pace RP, Vo D, Bartlett GA, Schmitt ES, Ward PA, Oermann C, Eng CM, Roa BB
Use of MALDI-TOF mass spectrometry in a 51-mutation test for cystic fibrosis: evidence that 3199del6 is a disease-causing mutation.
Genet Med. 2004 Sep-Oct;6(5):426-30., [PMID:15371908]

Abstract [show]
PURPOSE: We developed a 51-mutation extended cystic fibrosis (CF) panel that incorporates the 25 previously recommended CFTR mutations, plus 26 additional mutations including 3199del6, which was associated with I148T. METHODS: This assay utilizes an integrated matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry system. RESULTS: CF testing was performed on over 5,000 individuals, including a 3-year-old Hispanic-American patient with a compound heterozygous G542X/3199del6 genotype. He is negative for I148T, or other mutations assessed by CFTR gene sequencing. CONCLUSION: These results demonstrate the successful implementation of MALDI-TOF mass spectrometry in CF clinical testing, and establish 3199del6 as a disease-causing CF mutation.

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77 This assay also demonstrated heterozygosity for the G542X mutation, and reflex testing for the 5T variant at CFTR intron 8 showed a genotype of 7T/9T in this patient (data not Table 3 Description of the 16 multiplex assays designed to analyze 51 CFTR mutations Multiplex Mutations Exon 1 1078delT, G314E, R352Q, G330X 7 2 R347H, R347P, R334W, 1717-1A 7, 11 3 R553X, S549N, R1162X 11, 19 4 A559T, R560T, G551D 11 5 G542X, S549R, 621ϩ1T, Y122X 4, 11 6 W1282X, 3876delA, 3905insT, D1152H 18, 20 7 3849ϩ4G, 3659delC, 1898ϩ1A 12, 19 8 405ϩ1A, 405ϩ3C, 3120A, 3120ϩ1A 3, 16 9 394delTT, E60X, G85E 3 10 A455E, ⌬F508a 9, 10 11 G480C, Q493X, V520F 10 12 711ϩ1T, G178R, 3199del6 5, 17a 13 2143delT, 2184delA, K710X, F316L 7, 13 14 I148T, R117H, R117C 4 15 N1303K, 2789ϩ5A, 3849ϩ10kbT 14b, intron19, 21 16 ⌬I507a 10 17 5Tb intron 8 a F508C and I507V, I506V, I506M variants are tested for concurrently with the ⌬F508 and ⌬I507 assays respectively. Login to comment

[hide] Nucleotide binding domains of human CFTR: a struct... Cell Mol Life Sci. 2005 Sep;62(18):2112-23. Eudes R, Lehn P, Ferec C, Mornon JP, Callebaut I
Nucleotide binding domains of human CFTR: a structural classification of critical residues and disease-causing mutations.
Cell Mol Life Sci. 2005 Sep;62(18):2112-23., [PMID:16132229]

Abstract [show]
Defective function of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) causes CF, the most frequent lethal inherited disease among the Caucasian population. The structure of this chloride ion channel includes two nucleotide-binding domains (NBDs), whose ATPase activity controls channel gating. Recently, the experimental structures of mouse and human CFTR NBD1 and our model of the human CFTR NBD1/NBD2 heterodimer have provided new insights into specific structural features of the CFTR NBD dimer. In the present work, we provide a structural classification of CF-causing mutations which may complement the existing functional classification. Our analysis also identified amino acid residues which may play a critical role in interdomain interaction and are located at the NBD1-NBD2 interface or on the surface of the dimer. In particular, a cluster of aromatic amino acids, which includes F508 and straddles the two NBDs, might be directly involved in the interaction of the NBD1/NBD2 heterodimer with the channel-forming membrane-spanning domains.

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144 Another class II mutation, G480C, involves a non-buried position (labeled E in fig. 2). Login to comment
145 Similarly to ∆F508, the G480C mutant has been found to be defective in its intracellular processing and to exhibit chloride channel properties when allowed to traffic in Xenopus oocytes [46]. Login to comment
147 We should also stress here that both ∆F508 and G480C, which are class II mutations affecting residues possibly involved in domain-domain interactions, are considered as clinically severe mutations. Login to comment
148 Accordingly, mouse models carrying the severe ∆F508 and G480C mutations have been generated to provide valuable in vivo systems to test novel therapeutic approaches [47]. Login to comment
345 Nat. Struct. Mol. Biol. 12: 17-25 46 Smit L. S., Strong T. V., Wilkinson D. J., Macek M., Mansoura M. K., Wood D. L. et al. (1995) Missense mutation (G480C) in the CFTR gene associated with protein mislocalization but normal chloride channel activity. Login to comment

[hide] Cystic fibrosis mouse models. Am J Respir Cell Mol Biol. 2007 Jan;36(1):1-7. Epub 2006 Aug 3. Guilbault C, Saeed Z, Downey GP, Radzioch D
Cystic fibrosis mouse models.
Am J Respir Cell Mol Biol. 2007 Jan;36(1):1-7. Epub 2006 Aug 3., [PMID:16888286]

Abstract [show]
Animal models of cystic fibrosis (CF) are powerful tools that enable the study of the mechanisms and complexities of human disease. Murine models have several intrinsic advantages compared with other animal models, including lower cost, maintenance, and rapid reproduction rate. Mice can be easily genetically manipulated by making transgenic or knockout mice, or by backcrossing to well-defined inbred strains in a reasonably short period of time. However, anatomic and immunologic differences between mice and humans mean that murine models have inherent limitations that must be considered when interpreting the results obtained from experimental models and applying these to the pathogenesis of CF disease in humans. This review will focus on the different CF mouse models available that represent diverse phenotypes observed in humans with CF and that can help researchers elucidate the diverse functions of the CFTR protein.

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34 CYSTIC FIBROSIS MOUSE MODELS Mutation Usefulness CFTRtm1UNC Exon 10 replacement Survival rates, using a liquid-nutrient diet and colyte No CFTR mRNA detectable Transgenic mice containing FABP-hCFTR gene to correct intestinal disease Susceptibility to S. aureus, B. cepacia, P. aeruginosa Resistance to V. cholerae Congenic strain B6 (lung disease) and BALB/C CFTRtm1HGU Exon 10 insertional Susceptibility to S. aureus, B. cepacia, P.aeruginosa 10% of WT CFTR mRNA CFTRtm1CAM Exon 10 replacement Transgenic mice containing hCFTR gene to correct No CFTR mRNA detectable intestinal pathology Resistance to V. cholerae CFTRtm1BAY Exon 3 insertional duplication Ͻ 2% WT CFTR mRNA CFTRtm3BAY Exon 2 replacement No CFTR mRNA detectable CFTRtm1HSC Exon 1 replacement Modifying genes for meconium ileus No CFTR mRNA detectable CFTRtm1EUR ⌬F508 exon 10 insertional "hit and run" Mutant CFTR mRNA normal levels CFTRtm2CAM ⌬F508 exon 10 replacement Resistance to S. typhi Mutant CFTR mRNA 30% of WT levels CFTRtm1KTH ⌬F508 exon 10 replacement Susceptibility to P. aeruginosa Mutant CFTR mRNA Low in intestine CFTRtm1G551D G551D exon 11 replacement Susceptibility to P. aeruginosa Mutant CFTR mRNA 53% of WT levels CFTRtm2HGU G480C exon 10 insertional "hit and run" Mutant CFTR mRNA normal levels Definition of abbreviations: CFTR, cystic fibrosis transmembrane conductance regulator; WT, wild type. Login to comment
51 The most recent mouse model was developed to mimic the human G480C mutation (20). Login to comment
52 Dickinson and colleagues generated a G480C mouse model by inserting the mutation into exon 10 using a double homologous recombination technique. Login to comment

[hide] Animal models of chronic lung infection with Pseud... Lab Anim. 2008 Oct;42(4):389-412. Epub 2008 Sep 9. Kukavica-Ibrulj I, Levesque RC
Animal models of chronic lung infection with Pseudomonas aeruginosa: useful tools for cystic fibrosis studies.
Lab Anim. 2008 Oct;42(4):389-412. Epub 2008 Sep 9., [PMID:18782827]

Abstract [show]
Cystic fibrosis (CF) is caused by a defect in the transmembrane conductance regulator (CFTR) protein that functions as a chloride channel. Dysfunction of the CFTR protein results in salty sweat, pancreatic insufficiency, intestinal obstruction, male infertility and severe pulmonary disease. In most patients with CF life expectancy is limited due to a progressive loss of functional lung tissue. Early in life a persistent neutrophylic inflammation can be demonstrated in the airways. The cause of this inflammation, the role of CFTR and the cause of lung morbidity by different CF-specific bacteria, mostly Pseudomonas aeruginosa, are not well understood. The lack of an appropriate animal model with multi-organ pathology having the characteristics of the human form of CF has hampered our understanding of the pathobiology and chronic lung infections of the disease for many years. This review summarizes the main characteristics of CF and focuses on several available animal models that have been frequently used in CF research. A better understanding of the chronic lung infection caused particularly by P. aeruginosa, the pathophysiology of lung inflammation and the pathogenesis of lung disease necessitates animal models to understand CF, and to develop and improve treatment.

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163 To address this question, a collection of recombinant CF mouse models was generated containing clinically relevant mutations in CFTR by introducing specific human mutations into the equivalent mouse loci including DF508 (Colledge et al. 1995, van Doorninck et al. 1995, Zeiher et al. 1995, French et al. 1996), G551D (substitution of a glycine with an aspartic acid) (Delaney et al. 1996) and G480C (missense mutation) (Dickinson et al. 2000) (Table 2). Login to comment
170 Table 2 Cystic fibrosis (CF) mouse models CF mice Mutation/molecular strategy Phenotype/limitation CFTR KO CFTRtm1Unc (Snouwaert et al. 1992) Exon 10 replacement, null mutation, inframe stop Severe intestinal phenotype and high mortality; no lung disease CFTRtm1Hgu (Dorin et al. 1992) Exon 10 insertional mutagenesis Intestinal blockage; minor pathology in lungs of one mouse CFTRtm1Cam (Ratcliff et al. 1993) Exon 10 replacement, null mutation Severe intestinal phenotype and high mortality; pathology in lacrimal gland and pancreas of some mice; no lung disease CFTRtm1Bay (O`Neal et al. 1993) Exon 3 insertional duplication, null mutation Severe intestinal phenotype and high mortality; no lung disease CFTRtm1Hsc (Rozmahel et al. 1996) Exon 1 replacement, null mutation Severe intestinal phenotype and high mortality; no lung disease Other mutations CFTRtm1Kth (Zeiher et al. 1995) DF508 by exon 10 replacement High mortality and reduction in size, variable pathology of the gastrointestinal tract, normal lung, pancreas, gallbladder, male reproductive tract, lacrimal gland and submandibular glands CFTRtm1Eur (van Doorninck et al. 1995, French et al. 1996) DF508 by exon 10 'hit and run` Normal survival, growth retarded but no abnormalities or stasis of inspissated mucus in lungs, pancreas, liver bile ducts, vas deferens and salivary glands CFTRtm1G551D (Delaney et al. 1996) G551D by exon 11 replacement Moderate phenotype with reduced incidence of intestinal blockage and 67% survival; no lung disease CFTRtm2Hgu (Dickinson et al. 2000) G480C by exon 10 'hit and run` Normal survival, no reduction in body weight, preserved cAMP-mediated Cl2 response, decreased Ca2þ -related Cl2 response CFTR2/2hCFTR-G542X (Du et al. 2002) CFTR2/2 null mutation that also express a human CFTR-G542X stop mutation under control of the intestinal FABP promoter Suppression of the hCFTR-G542X mutation in vivo by aminoglycosides CFTRtm1Unc -TgN(FABPCFTR) (Zhou et al. 1994) Stop codon in the murine CFTR gene (S489X) but also express human CFTR in the gut epithelium (transgenic introduction of CFTR under FABP promoter) Functional correction of ileal goblet cell and crypt cell hyperplasia and cyclic adenosine monophosphate-stimulated chloride secretion, improved survival Congenic C57BL/6J CFTR2/2 (Durie et al. 2004) Long-lived congenic C57BL/6J CFTR2/2 All organs pathologically affected by the human form of CF Scnn1a-, Scnn1b- and Scnn1c-transgenic mice (Mall et al. 2004) Transgenic mice overexpressing airway-specific ENaC to increase Naþ absorption CF-like lung disease FABP: fatty acid-binding protein, ENaC: epithelial Naþ channels. Login to comment

[hide] Mutations that permit residual CFTR function delay... Respir Res. 2010 Oct 8;11:140. Green DM, McDougal KE, Blackman SM, Sosnay PR, Henderson LB, Naughton KM, Collaco JM, Cutting GR
Mutations that permit residual CFTR function delay acquisition of multiple respiratory pathogens in CF patients.
Respir Res. 2010 Oct 8;11:140., [PMID:20932301]

Abstract [show]
BACKGROUND: Lung infection by various organisms is a characteristic feature of cystic fibrosis (CF). CFTR genotype effects acquisition of Pseudomonas aeruginosa (Pa), however the effect on acquisition of other infectious organisms that frequently precede Pa is relatively unknown. Understanding the role of CFTR in the acquisition of organisms first detected in patients may help guide symptomatic and molecular-based treatment for CF. METHODS: Lung infection, defined as a single positive respiratory tract culture, was assessed for 13 organisms in 1,381 individuals with CF. Subjects were divided by predicted CFTR function: 'Residual': carrying at least one partial function CFTR mutation (class IV or V) and 'Minimal' those who do not carry a partial function mutation. Kaplan-Meier estimates were created to assess CFTR effect on age of acquisition for each organism. Cox proportional hazard models were performed to control for possible cofactors. A separate Cox regression was used to determine whether defining infection with Pa, mucoid Pa or Aspergillus (Asp) using alternative criteria affected the results. The influence of severity of lung disease at the time of acquisition was evaluated using stratified Cox regression methods by lung disease categories. RESULTS: Subjects with 'Minimal' CFTR function had a higher hazard than patients with 'Residual' function for acquisition of 9 of 13 organisms studied (HR ranging from 1.7 to 3.78 based on the organism studied). Subjects with minimal CFTR function acquired infection at a younger age than those with residual function for 12 of 13 organisms (p-values ranging: < 0.001 to 0.017). Minimal CFTR function also associated with younger age of infection when 3 alternative definitions of infection with Pa, mucoid Pa or Asp were employed. Risk of infection is correlated with CFTR function for 8 of 9 organisms in patients with good lung function (>90%ile) but only 1 of 9 organisms in those with poorer lung function (<50%ile). CONCLUSIONS: Residual CFTR function correlates with later onset of respiratory tract infection by a wide spectrum of organisms frequently cultured from CF patients. The protective effect conferred by residual CFTR function is diminished in CF patients with more advanced lung disease.

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74 For Pa, the hazard ratio Table 1 Classification of CFTR alleles Category Mutation Specific mutations Class I Defective Protein Synthesis (nonsense, frameshift, aberrant splicing) 1078delT, 1154 insTC, 1525-2A > G, 1717-1G > A, 1898+1G > A, 2184delA, 2184 insA, 3007delG, 3120+1G > A, 3659delC, 3876delA, 3905insT, 394delTT, 4010del4, 4016insT, 4326delTC, 4374+1G > T, 441delA, 556delA, 621+1G > T, 621-1G > T, 711+1G > T, 875+1G > C, E1104X, E585X, E60X, E822X, G542X, G551D/R553X, Q493X, Q552X, Q814X, R1066C, R1162X, R553X, V520F, W1282X, Y1092X Class II Abnormal Processing and Trafficking A559T, D979A, ΔF508, ΔI507, G480C, G85E, N1303K, S549I, S549N, S549R Class III Defective Channel Regulation/Gating G1244E, G1349D, G551D, G551S, G85E, H199R, I1072T, I48T, L1077P, R560T, S1255P, S549 (R75Q) Class IV Decreased Channel Conductance A800G, D1152H, D1154G, D614G, delM1140, E822K, G314E, G576A, G622D, G85E, H620Q, I1139V, I1234V, L1335P, M1137V, P67L, R117C, R117P, R117H, R334W, R347H, R347P, R347P/ R347H, R792G, S1251N, V232D Class V Reduced Synthesis and/or Trafficking 2789+5G > A, 3120G > A, 3272-26A > G, 3849+10kbC > T, 5T variant, 621+3A > G, 711+3A > G, A445E, A455E, IVS8 poly T, P574H was increased 3 fold for those with 'Minimal` function when compared to those with 'Residual` function. Login to comment

[hide] CFTR-dependent susceptibility of the cystic fibros... Int J Med Microbiol. 2010 Dec;300(8):578-83. Epub 2010 Oct 14. Grassme H, Becker KA, Zhang Y, Gulbins E
CFTR-dependent susceptibility of the cystic fibrosis-host to Pseudomonas aeruginosa.
Int J Med Microbiol. 2010 Dec;300(8):578-83. Epub 2010 Oct 14., [PMID:20951085]

Abstract [show]
Cystic fibrosis is the most common autosomal recessive disorder in western countries. The disease is characterized by recurrent and chronic infections of the lung in particular with Pseudomonas aeruginosa, Staphylococcus aureus, Burkholderia cepacia, and Haemophilus influenzae. Albeit intensive research in the last years, the molecular mechanisms causing the high susceptibility of cystic fibrosis patients to bacterial infections are still unknown. Animal models provided important novel information on the pathophysiology of cystic fibrosis and mimicked many of the pathological findings in humans, for instance chronic inflammation and increased infection susceptibility. These animal models were recently employed to identify several proteins and lipids that are critically involved in the pathophysiology of cystic fibrosis. Thus, several studies identified death receptors, caveolin proteins, membrane rafts, and alterations of the ceramide metabolism with an accumulation of ceramide in cystic fibrosis lungs to be critically involved in the infection susceptibility, the chronic inflammation, and the reduced mucociliary clearance in cystic fibrosis.

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36 Several mouse models of the human mutations F508, G551D, and G480C were also generated by insertion of the corresponding mutation into exon 10 or exon 11, respectively. Login to comment

[hide] Mouse models of cystic fibrosis: phenotypic analys... J Cyst Fibros. 2011 Jun;10 Suppl 2:S152-71. Wilke M, Buijs-Offerman RM, Aarbiou J, Colledge WH, Sheppard DN, Touqui L, Bot A, Jorna H, de Jonge HR, Scholte BJ
Mouse models of cystic fibrosis: phenotypic analysis and research applications.
J Cyst Fibros. 2011 Jun;10 Suppl 2:S152-71., [PMID:21658634]

Abstract [show]
Genetically modified mice have been studied for more than fifteen years as models of cystic fibrosis (CF). The large amount of experimental data generated illuminates the complex multi-organ pathology of CF and raises new questions relevant to human disease. CF mice have also been used to test experimental therapies prior to clinical trials. This review recapitulates the major phenotypic traits of CF mice and highlights important new findings including aberrant alveolar macrophages, bone and cartilage abnormalities and abnormal bioactive lipid metabolism. Novel data are presented on the intestinal and nasal physiology of F508del-CFTR CF mice backcrossed onto different genetic backgrounds. Caveats, and sources of variability including age, gender and animal husbandry, are discussed. Interspecies differences limit comparison of lung pathology in CF mice to the human disease. The recent development of genetically modified pigs and ferrets heralds the application of more advanced animal models to CF research and drug development.

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67 Unfortunately, there is no Table 1 CFTR mutant mice Mouse Mutation Cftr mRNA Genetic Survival to Body wt Contact References background maturity Null mutations Cftrtm1Unc S489X Ex10 R Not detectable* C57Bl/6 <5% 10-25% reduction BH Koller/Jax Labs [113,158] Cftrtm1Cam R487X Ex10 R Not detectable 129S6/Sv/Ev <5% 20% reduction WH Colledge [159] Cftrtm1Hsc M1X Ex1 R Not detectable CD1 x 129 25% Delayed LC Tsui [160] Cftrtm3Bay Ex2 R Not detectable C57Bl/6 x 129 40% Reduced AT Beaudet [161] Cftrtm3Uth Y122X Ex4 R Not detectable C57Bl/6 25% 25-50% reduction M Capecchi/PB Davis [113,162] Hypomorphic mutations Cftrtm1Hgu ** Ex10 I 10% of wt MF1 x 129 90% No reduction J Dorin [113] Cftrtm1Bay Ex3 I <2% wt C57Bl/6 x 129 40% 70% reduction AL Beaudet [163] F508del mutations Cftrtm2Cam F508del R 30% of wt 129S6/Sv/Ev <5% 10-20% reduction WH Colledge [164] Cftrtm1Kth F508del R Low in intestine C57Bl/6 x 129 40% 10-50% reduction KR Thomas/Jax labs [165] Cftrtm1Eur F508del (H&R) Normal levels FVB/129; FVB 90% 10-20% reduction BJ Scholte [9] C57Bl/6 Other point mutations Cftrtm2Hgu G551D R 50% of wt CD1/129 65% 30-50% reduction J Dorin [11] Cftrtm3Hgu G480C (H&R) Normal levels C57Bl/6/129 Normal No reduction J Dorin [166] Cftrtm2Uth R117H R 5-20% of wt C57/Bl6 95% 10-25% reduction M Capecchi/PB Davis [113,162] Transgenes Mouse Transgene Promoter Expression Phenotype References Tg(FABPCFTR) CFTR Rat intestinal fatty acid Intestinal villus epithelia Rescue of CF intestinal pathology [167] binding protein Tg(CCSPScnn1b) Scnn1b Clara cell secretory Airway surface epithelia Na+ hyperabsorption [13] protein (CCSP) Reduced airway surface fluid volume Mucus accumulation, CF-like lung disease; 40% survival. Login to comment
890 [166] Dickinson P, Smith SN, Webb S, et al. The severe G480C cystic fibrosis mutation, when replicated in the mouse, demonstrates mistrafficking, normal survival and organ-specific bioelectrics. Login to comment

[hide] Genetics and pulmonary medicine. 1. The genetics o... Thorax. 1998 May;53(5):389-97. Davidson DJ, Porteous DJ
Genetics and pulmonary medicine. 1. The genetics of cystic fibrosis lung disease.
Thorax. 1998 May;53(5):389-97., [PMID:9708232]

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16 Mutations in CFTR may result in: (1) defective CFTR production, such as R553X, due to unstable mRNA and/or premature protein truncation, (2) defective processing of CFTR, such as F508 or G480C, where the mutant protein is not processed to its mature glycosylated form and is not correctly localised to the apical membrane, but is retained in the endoplasmic reticulum and degraded. Login to comment
17 However, under permissive conditions in vitro, such as reduced temperature, correct localisation of mature protein can occur where it can function normally (in the case of G480C), or suboptimally (in the case of F508), or (3) defective ion channel function, such as G551D or R117H, in which case some of the mutant protein becomes correctly localised but results in either very little residual function (in the case of G551D) or a substantially reduced level of ion transport (in the case of R117H). Login to comment

[hide] Pathology of pancreatic and intestinal disorders i... J R Soc Med. 1998;91 Suppl 34:40-9. Wilschanski M, Durie PR
Pathology of pancreatic and intestinal disorders in cystic fibrosis.
J R Soc Med. 1998;91 Suppl 34:40-9., [PMID:9709387]

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152 A small number of more Table 1 Classification of cystic fibrosis gene mutation as severe, mild or indeterminate with respect to pancreatic function Severe Mild Variable (classes 1, I/ or 111) (classes IV or V) (classes IV or V) AF508 R117H G85E 1148T R334W 2789+5G-*A G480C R347P G551D A455E R560T P574H N1303K 3849+1 Okb C-+T G542X G551S W1282X P5748 621 +1 G-T R352Q 1717-1G-T T3381 556delA Adapted from Ref 20 with permission recently described mutations [G85E and 278+5G-÷AI are less clearly determinant with respect to the pancreatic sufficient and pancreatic insufficient phenotypes. Login to comment

[hide] Pharmacology of CFTR chloride channel activity. Physiol Rev. 1999 Jan;79(1 Suppl):S109-44. Schultz BD, Singh AK, Devor DC, Bridges RJ
Pharmacology of CFTR chloride channel activity.
Physiol Rev. 1999 Jan;79(1 Suppl):S109-44., [PMID:9922378]

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Pharmacology of CFTR Chloride Channel Activity. Physiol. Rev. 79, Suppl.: S109-S144, 1999. - The pharmacology of cystic fibrosis transmembrane conductance regulator (CFTR) is at an early stage of development. Here we attempt to review the status of those compounds that modulate the Cl- channel activity of CFTR. Three classes of compounds, the sulfonylureas, the disulfonic stilbenes, and the arylaminobenzoates, have been shown to directly interact with CFTR to cause channel blockade. Kinetic analysis has revealed the sulfonylureas and arylaminobenzoates interact with the open state of CFTR to cause blockade. Suggestive evidence indicates the disulfonic stilbenes act by a similar mechanism but only from the intracellular side of CFTR. Site-directed mutagenesis studies indicate the involvement of specific amino acid residues in the proposed transmembrane segment 6 for disulfonic stilbene blockade and segments 6 and 12 for arylaminobenzoate blockade. Unfortunately, these compounds (sulfonylureas, disulfonic stilbenes, arylaminobenzoate) also act at a number of other cellular sites that can indirectly alter the activity of CFTR or the transepithelial secretion of Cl-. The nonspecificity of these compounds has complicated the interpretation of results from cellular-based experiments. Compounds that increase the activity of CFTR include the alkylxanthines, phosphodiesterase inhibitors, phosphatase inhibitors, isoflavones and flavones, benzimidazolones, and psoralens. Channel activation can arise from the stimulation of the cAMP signal transduction cascade, the inhibition of inactivating enzymes (phosphodiesterases, phosphatases), as well as the direct binding to CFTR. However, in contrast to the compounds that block CFTR, a detailed understanding of how the above compounds increase the activity of CFTR has not yet emerged.

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293 There are, as a result of these drug development efforts, a number of isoform-specific PDEon to show that the missense mutation G480C associated with CFTR protein mislocalization was equally sensitive inhibitors that are in clinical use. Login to comment

[hide] Cystic fibrosis carrier frequencies in populations... J Med Genet. 1999 Jan;36(1):41-4. Padoa C, Goldman A, Jenkins T, Ramsay M
Cystic fibrosis carrier frequencies in populations of African origin.
J Med Genet. 1999 Jan;36(1):41-4., [PMID:9950364]

Abstract [show]
Cystic fibrosis (CF) is a common autosomal recessive disorder in populations of European descent. However, very little is known about CF in populations of African origin among whom it has been believed to be extremely rare. The aim of this study was to determine if this is the case or whether it is under-reported. A CFTR mutation, 3120+1G-->A, which was first reported in three African-American CF patients, has been shown to account for 9-14% of African-American CF chromosomes. It has also been found in 4/6 CF chromosomes in South African blacks and one CF chromosome of Cameroonian origin. In order to determine the carrier frequency of the 3120+1G-->A mutation in Africa, 1360 unrelated, healthy subjects were screened. Nine carriers were identified. In addition, two out of five black CF patients with positive sweat tests were found to be heterozygous for the 3120+1G-->A mutation and two out of another four black patients with symptoms suggestive of CF, but unconfirmed by sweat tests, were heterozygous for the D1270N mutation. A further three CFTR mutations, A559T, S1255X, and 444delA, which had been found in African-American CF patients, were not identified in the patients or in over 373 healthy subjects tested. The 3120+1G-->A mutation has a carrier frequency of 1 in 91 (8/728) in South African blacks with a 95% confidence interval of 1 in 46 to 1 in 197. Since this mutation accounts for between 15% and 65% of CF chromosomes in South African blacks, a corrected CF carrier frequency would be between 1 in 14 and 1 in 59. Hence, the incidence of CF would be predicted to be between 1 in 784 and 1 in 13924 births in this population. There are several possible reasons why these people are not being detected. Some of these are misdiagnosis as chronic pulmonary infection, malnutrition, tuberculosis, infantile diarrhoea, failure to thrive, or a high infant mortality rate.

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15 Together, eight mutations (405+3A→C, 444delA, G480C, R553X, A559T, 2307insA, 3120+1G→A, and S1255X) account for 23.1% of African-American CF chromosomes. Login to comment

[hide] Rescue of functional delF508-CFTR channels in cyst... FEBS Lett. 2006 Apr 3;580(8):2081-6. Epub 2006 Mar 10. Norez C, Noel S, Wilke M, Bijvelds M, Jorna H, Melin P, DeJonge H, Becq F
Rescue of functional delF508-CFTR channels in cystic fibrosis epithelial cells by the alpha-glucosidase inhibitor miglustat.
FEBS Lett. 2006 Apr 3;580(8):2081-6. Epub 2006 Mar 10., [PMID:16546175]

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In the disease cystic fibrosis (CF), the most common mutation delF508 results in endoplasmic reticulum retention of misfolded CF gene proteins (CFTR). We show that the alpha-1,2-glucosidase inhibitor miglustat (N-butyldeoxynojirimycin, NB-DNJ) prevents delF508-CFTR/calnexin interaction and restores cAMP-activated chloride current in epithelial CF cells. Moreover, miglustat rescues a mature and functional delF508-CFTR in the intestinal crypts of ileal mucosa from delF508 mice. Since miglustat is an orally active orphan drug (Zavesca) prescribed for the treatment of Gaucher disease, our findings provide the basis for future clinical evaluation of miglustat in CF patients.

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131 For example, with the G480C trafficking mutant %8% of mature CFTR protein is associated to %40% residual cAMP-stimulated chloride secretion in mice intestine [25]. Login to comment

[hide] Genotyping microarray for the detection of more th... J Mol Diagn. 2005 Aug;7(3):375-87. Schrijver I, Oitmaa E, Metspalu A, Gardner P
Genotyping microarray for the detection of more than 200 CFTR mutations in ethnically diverse populations.
J Mol Diagn. 2005 Aug;7(3):375-87., [PMID:16049310]

Abstract [show]
Cystic fibrosis (CF), which is due to mutations in the cystic fibrosis transmembrane conductance regulator gene, is a common life-shortening disease. Although CF occurs with the highest incidence in Caucasians, it also occurs in other ethnicities with variable frequency. Recent national guidelines suggest that all couples contemplating pregnancy should be informed of molecular screening for CF carrier status for purposes of genetic counseling. Commercially available CF carrier screening panels offer a limited panel of mutations, however, making them insufficiently sensitive for certain groups within an ethnically diverse population. This discrepancy is even more pronounced when such carrier screening panels are used for diagnostic purposes. By means of arrayed primer extension technology, we have designed a genotyping microarray with 204 probe sites for CF transmembrane conductance regulator gene mutation detection. The arrayed primer extension array, based on a platform technology for disease detection with multiple applications, is a robust, cost-effective, and easily modifiable assay suitable for CF carrier screening and disease detection.

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51 Complete List of Mutations Detectable with the CF APEX Assay CFTR location Amino acid change Nucleotide change 1 E 1 Frameshift 175delC 2 E 2,3 Frameshift del E2, E3 3 E 2 W19C 189 GϾT 4 E 2 Q39X 247 CϾT 5 IVS 2 Possible splicing defect 296 ϩ 12 TϾC 6 E 3 Frameshift 359insT 7 E 3 Frameshift 394delTT 8 E 3 W57X (TAG) 302GϾA 9 E 3 W57X (TGA) 303GϾA 10 E 3 E60X 310GϾT 11 E 3 P67L 332CϾT 12 E 3 R74Q 353GϾA 13 E 3 R75X 355CϾT 14 E 3 G85E 386GϾA 15 E 3 G91R 403GϾA 16 IVS 3 Splicing defect 405 ϩ 1GϾA 17 IVS 3 Possible splicing defect 405 ϩ 3AϾC 18 IVS 3 Splicing defect 406 - 1GϾA 19 E 4 E92X 406GϾT 20 E 4 E92K 406GϾA 21 E 4 Q98R 425AϾG 22 E 4 Q98P 425AϾC 23 E 4 Frameshift 444delA 24 E 4 Frameshift 457TATϾG 25 E 4 R117C 481CϾT 26 E 4 R117H 482GϾA 27 E 4 R117P 482GϾC 28 E 4 R117L 482GϾT 29 E 4 Y122X 498TϾA 30 E 4 Frameshift 574delA 31 E 4 I148T 575TϾC 32 E 4 Splicing defect 621GϾA 33 IVS 4 Splicing defect 621 ϩ 1GϾT 34 IVS 4 Splicing defect 621 ϩ 3AϾG 35 E 5 Frameshift 624delT 36 E 5 Frameshift 663delT 37 E 5 G178R 664GϾA 38 E 5 Q179K 667CϾA 39 IVS 5 Splicing defect 711 ϩ 1GϾT 40 IVS 5 Splicing defect 711 ϩ 1GϾA 41 IVS 5 Splicing defect 712 - 1GϾT 42 E 6a H199Y 727CϾT 43 E 6a P205S 745CϾT 44 E 6a L206W 749TϾG 45 E 6a Q220X 790CϾT 46 E 6b Frameshift 935delA 47 E 6b Frameshift 936delTA 48 E 6b N287Y 991AϾT 49 IVS 6b Splicing defect 1002 - 3TϾG 50 E 7 ⌬F311 3-bp del between nucleotides 1059 and 1069 51 E 7 Frameshift 1078delT 52 E 7 Frameshift 1119delA 53 E 7 G330X 1120GϾT 54 E 7 R334W 1132CϾT 55 E 7 I336K 1139TϾA 56 E 7 T338I 1145CϾT 57 E 7 Frameshift 1154insTC 58 E 7 Frameshift 1161delC 59 E 7 L346P 1169TϾC 60 E 7 R347H 1172GϾA 61 E 7 R347P 1172GϾC 62 E 7 R347L 1172GϾT 63 E 7 R352Q 1187GϾA 64 E 7 Q359K/T360K 1207CϾA and 1211CϾA 65 E 7 S364P 1222TϾC 66 E 8 Frameshift 1259insA 67 E 8 W401X (TAG) 1334GϾA 68 E 8 W401X (TGA) 1335GϾA 69 IVS 8 Splicing changes 1342 - 6 poly(T) variants 5T/7T/9T 70 IVS 8 Splicing defect 1342 - 2AϾC Table 1. Continued CFTR location Amino acid change Nucleotide change 71 E 9 A455E 1496CϾA 72 E 9 Frameshift 1504delG 73 E 10 G480C 1570GϾT 74 E 10 Q493X 1609CϾT 75 E 10 Frameshift 1609delCA 76 E 10 ⌬I507 3-bp del between nucleotides 1648 and 1653 77 E 10 ⌬F508 3-bp del between nucleotides 1652 and 1655 78 E 10 Frameshift 1677delTA 79 E 10 V520F 1690GϾT 80 E 10 C524X 1704CϾA 81 IVS 10 Possible splicing defect 1717 - 8GϾA 82 IVS 10 Splicing defect 1717 - 1GϾA 83 E 11 G542X 1756GϾT 84 E 11 G551D 1784GϾA 85 E 11 Frameshift 1784delG 86 E 11 S549R (AϾC) 1777AϾC 87 E 11 S549I 1778GϾT 88 E 11 S549N 1778GϾA 89 E 11 S549R (TϾG) 1779TϾG 90 E 11 Q552X 1786CϾT 91 E 11 R553X 1789CϾT 92 E 11 R553G 1789CϾG 93 E 11 R553Q 1790GϾA 94 E 11 L558S 1805TϾC 95 E 11 A559T 1807GϾA 96 E 11 R560T 1811GϾC 97 E 11 R560K 1811GϾA 98 IVS 11 Splicing defect 1811 ϩ 1.6 kb AϾG 99 IVS 11 Splicing defect 1812 - 1GϾA 100 E 12 Y563D 1819TϾG 101 E 12 Y563N 1819TϾA 102 E 12 Frameshift 1833delT 103 E 12 D572N 1846GϾA 104 E 12 P574H 1853CϾA 105 E 12 T582R 1877CϾG 106 E 12 E585X 1885GϾT 107 IVS 12 Splicing defect 1898 ϩ 5GϾT 108 IVS 12 Splicing defect 1898 ϩ 1GϾA 109 IVS 12 Splicing defect 1898 ϩ 1GϾC 110 IVS 12 Splicing defect 1898 ϩ 1GϾT 111 E 13 Frameshift 1924del7 112 E 13 del of 28 amino acids 1949del84 113 E 13 I618T 1985TϾC 114 E 13 Frameshift 2183AAϾG 115 E 13 Frameshift 2043delG 116 E 13 Frameshift 2055del9ϾA 117 E 13 D648V 2075TϾA 118 E 13 Frameshift 2105-2117 del13insAGAA 119 E 13 Frameshift 2108delA 120 E 13 R668C 2134CϾT 121 E 13 Frameshift 2143delT 122 E 13 Frameshift 2176insC 123 E 13 Frameshift 2184delA 124 E 13 Frameshift 2184insA 125 E 13 Q685X 2185CϾT 126 E 13 R709X 2257CϾT 127 E 13 K710X 2260AϾT 128 E 13 Frameshift 2307insA 129 E 13 V754M 2392GϾA 130 E 13 R764X 2422CϾT 131 E 14a W846X 2670GϾA 132 E 14a Frameshift 2734delGinsAT 133 E 14b Frameshift 2766del8 134 IVS 14b Splicing defect 2789 ϩ 5GϾA 135 IVS 14b Splicing defect 2790 - 2AϾG 136 E 15 Q890X 2800CϾT 137 E 15 Frameshift 2869insG 138 E 15 S945L 2966CϾT 139 E 15 Frameshift 2991del32 140 E 16 Splicing defect 3120GϾA interrogation: ACCAACATGTTTTCTTTGATCTTAC 3121-2A3G,T S; 5Ј-ACCAACATGTTTTCTTTGATCTTAC A GTTGTTATTAATTGTGATTGGAGCTATAG-3Ј; CAACAA- TAATTAACACTAACCTCGA 3121-2A3G,T AS. Login to comment
150 Primers Generated to Create Synthetic Templates That Serve As Positive Mutation Controls Primer name Sense strand 5Ј 3 3Ј Name Antisense strand 5Ј 3 3Ј 175delC synt F T(15)ATTTTTTTCAGGTGAGAAGGTGGCCA 175delC synt R T(15)ATTTGGAGACAACGCTGGCCTTTTCC W19C synt F T(15)TACCAGACCAATTTTGAGGAAAGGAT W19C synt R T(15)ACAGCTAAAATAAAGAGAGGAGGAAC Q39X synt F T(15)TAAATCCCTTCTGTTGATTCTGCTGA Q39X synt R T(15)AGTATATGTCTGACAATTCCAGGCGC 296 ϩ 12TϾC synt F T(15)CACATTGTTTAGTTGAAGAGAGAAAT 296 ϩ 12TϾC synt R T(15)GCATGAACATACCTTTCCAATTTTTC 359insT synt F T(15)TTTTTTTCTGGAGATTTATGTTCTAT 359insT synt R T(15)AAAAAAACATCGCCGAAGGGCATTAA E60X synt F T(15)TAGCTGGCTTCAAAGAAAAATCCTAA E60X synt R T(15)ATCTATCCCATTCTCTGCAAAAGAAT P67L synt F T(15)TTAAACTCATTAATGCCCTTCGGCGA P67L synt R T(15)AGATTTTTCTTTGAAGCCAGCTCTCT R74Q synt F T(15)AGCGATGTTTTTTCTGGAGATTTATG R74Q synt R T(15)TGAAGGGCATTAATGAGTTTAGGATT R75X synt F T(15)TGATGTTTTTTCTGGAGATTTATGTT R75X synt R T(15)ACCGAAGGGCATTAATGAGTTTAGGA W57X(TAG) synt F T(15)AGGATAGAGAGCTGGCTTCAAAGAAA W57X(TAG) synt R T(15)TATTCTCTGCAAAAGAATAAAAAGTG W57X(TGA) synt F T(15)AGATAGAGAGCTGGCTTCAAAGAAAA W57X(TGA) synt R T(15)TCATTCTCTGCAAAAGAATAAAAAGT G91R synt F T(15)AGGGTAAGGATCTCATTTGTACATTC G91R synt R T(15)TTAAATATAAAAAGATTCCATAGAAC 405 ϩ 1GϾA synt F T(15)ATAAGGATCTCATTTGTACATTCATT 405 ϩ 1GϾA synt R T(15)TCCCTAAATATAAAAAGATTCCATAG 405 ϩ 3AϾC synt F T(15)CAGGATCTCATTTGTACATTCATTAT 405 ϩ 3AϾC synt R T(15)GACCCCTAAATATAAAAAGATTCCAT 406 - 1GϾA synt F T(15)AGAAGTCACCAAAGCAGTACAGCCTC 406 - 1GϾA synt R T(15)TTACAAAAGGGGAAAAACAGAGAAAT E92X synt F T(15)TAAGTCACCAAAGCAGTACAGCCTCT E92X synt R T(15)ACTACAAAAGGGGAAAAACAGAGAAA E92K synt F T(15)AAAGTCACCAAAGCAGTACAGCCTCT E92K synt R T(15)TCTACAAAAGGGGAAAAACAGAGAAA 444delA synt F T(15)GATCATAGCTTCCTATGACCCGGATA 444delA synt R T(15)ATCTTCCCAGTAAGAGAGGCTGTACT 574delA synt F T(15)CTTGGAATGCAGATGAGAATAGCTAT 574delA synt R T(15)AGTGATGAAGGCCAAAAATGGCTGGG 621GϾA synt F T(15)AGTAATACTTCCTTGCACAGGCCCCA 621GϾA synt R T(15)TTTCTTATAAATCAAACTAAACATAG Q98P synt F T(15)CGCCTCTCTTACTGGGAAGAATCATA Q98P synt R T(15)GGTACTGCTTTGGTGACTTCCTACAA 457TATϾG synt F T(15)GGACCCGGATAACAAGGAGGAACGCT 457TATϾG synt R T(15)CGGAAGCTATGATTCTTCCCAGTAAG I148T synt F T(15)CTGGAATGCAGATGAGAATAGCTATG I148T synt R T(15)GTGTGATGAAGGCCAAAAATGGCTGG 624delT synt F T(15)CTTAAAGCTGTCAAGCCGTGTTCTAG 624delT synt R T(15)TAAGTCTAAAAGAAAAATGGAAAGTT 663delT synt F T(15)ATGGACAACTTGTTAGTCTCCTTTCC 663delT synt R T(15)CATACTTATTTTATCTAGAACACGGC G178R synt F T(15)AGACAACTTGTTAGTCTCCTTTCCAA G178R synt R T(15)TAATACTTATTTTATCTAGAACACGG Q179K synt F T(15)AAACTTGTTAGTCTCCTTTCCAACAA Q179K synt R T(15)TTCCAATACTTATTTTATCTAGAACA 711 ϩ 5GϾA synt F T(15)ATACCTATTGATTTAATCTTTTAGGC 711 ϩ 5GϾA synt R T(15)TTATACTTCATCAAATTTGTTCAGGT 712 - 1GϾT synt F T(15)TGGACTTGCATTGGCACATTTCGTGT 712 - 1GϾT synt R T(15)TATGGAAAATAAAAGCACAGCAAAAAC H199Y synt F T(15)TATTTCGTGTGGATCGCTCCTTTGCA H199Y synt R T(15)TATGCCAATGCTAGTCCCTGGAAAATA P205S synt F T(15)TCTTTGCAAGTGGCACTCCTCATGGG P205S synt R T(15)TAAGCGATCCACACGAAATGTGCCAAT L206W synt F T(15)GGCAAGTGGCACTCCTCATGGGGCTA L206W synt R T(15)TCAAGGAGCGATCCACACGAAATGTGC Q220X synt F T(15)TAGGCGTCTGCTTTCTGTGGACTTGG Q220X synt R T(15)TATAACAACTCCCAGATTAGCCCCATG 936delTA synt F T(15)AATCCAATCTGTTAAGGCATACTGCT 936delTA synt R T(15)TGATTTTCAATCATTTCTGAGGTAATC 935delA synt F T(15)GAAATATCCAATCTGTTAAGGCATAC 935delA synt R T(15)TATTTCAATCATTTCTGAGGTAATCAC N287Y synt F T(15)TACTTAAGACAGTAAGTTGTTCCAAT N287Y synt R T(15)TATTCAATCATTTTTTCCATTGCTTCT 1002 - 3TϾG synt F T(15)GAGAACAGAACTGAAACTGACTCGGA 1002 - 3TϾG synt R T(15)TCTAAAAAACAATAACAATAAAATTCA 1154insTC syntwt F T(15)ATCTCATTCTGCATTGTTCTGCGCAT 1154insTC syntwt R T(15)TTGAGATGGTGGTGAATATTTTCCGGA 1154insTC syntmt F T(15)TCTCTCATTCTGCATTGTTCTGCGCAT 1154insTC syntmt R T(15)TAGAGATGGTGGTGAATATTTTCCGGA DF311 mt syntV1 F T(15)CCTTCTTCTCAGGGTTCTTTGTGGTG dF311 mt syntV1 R T(15)GAGAAGAAGGCTGAGCTATTGAAGTATC G330X synt F T(15)TGAATCATCCTCCGGAAAATATTCAC G330X synt R T(15)ATTTGATTAGTGCATAGGGAAGCACA S364P synt F T(15)CCTCTTGGAGCAATAAACAAAATACA S364P synt R T(15)GGTCATACCATGTTTGTACAGCCCAG Q359K/T360K mt synt F T(15)AAAAAATGGTATGACTCTCTTGGAGC Q359K/T360K mt synt R T(15)TTTTTTACAGCCCAGGGAAATTGCCG 1078delT synt F T(15)CTTGTGGTGTTTTTATCTGTGCTTCC 1078delT synt R T(15)CAAGAACCCTGAGAAGAAGAAGGCTG 1119delA synt F T(15)CAAGGAATCATCCTCCGGAAAATATT 1119delA synt R T(15)CTTGATTAGTGCATAGGGAAGCACAG 1161delC synt F T(15)GATTGTTCTGCGCATGGCGGTCACTC 1161delC synt R T(15)TCAGAATGAGATGGTGGTGAATATTT T338I synt F T(15)TCACCATCTCATTCTGCATTGTTCTG T338I synt R T(15)ATGAATATTTTCCGGAGGATGATTCC R352Q synt F T(15)AGCAATTTCCCTGGGCTGTACAAACA R352Q synt R T(15)TGAGTGACCGCCATGCGCAGAACAAT L346P synt F T(15)CGCGCATGGCGGTCACTCGGCAATTT L346P synt R T(15)GGAACAATGCAGAATGAGATGGTGGT 1259insA synt F T(15)AAAAAGCAAGAATATAAGACATTGGA 1259insA synt R T(15)TTTTTGTAAGAAATCCTATTTATAAA W401X(TAG)mtsynt F T(15)AGGAGGAGGTCAGAATTTTTAAAAAA W401X(TAG)mtsynt R T(15)TAGAAGGCTGTTACATTCTCCATCAC W401X(TGA) synt F T(15)AGAGGAGGTCAGAATTTTTAAAAAAT W401X(TGA) synt R T(15)TCAGAAGGCTGTTACATTCTCCATCA 1342 - 2AϾC synt F T(15)CGGGATTTGGGGAATTATTTGAGAAA 1342 - 2AϾC synt R T(15)GGTTAAAAAAACACACACACACACAC 1504delG synt F T(15)TGATCCACTGTAGCAGGCAAGGTAGT 1504delG synt R T(15)TCAGCAACCGCCAACAACTGTCCTCT G480C synt F T(15)TGTAAAATTAAGCACAGTGGAAGAAT G480C synt R T(15)ACTCTGAAGGCTCCAGTTCTCCCATA C524X synt F T(15)ACAACTAGAAGAGGTAAGAAACTATG C524X synt R T(15)TCATGCTTTGATGACGCTTCTGTATC V520F synt F T(15)TTCATCAAAGCAAGCCAACTAGAAGA V520F synt R T(15)AGCTTCTGTATCTATATTCATCATAG 1609delCA synt F T(15)TGTTTTCCTGGATTATGCCTGGCACC 1609delCA synt R T(15)CAGAACAGAATGAAATTCTTCCACTG 1717 - 8GϾA synt F T(15)AGTAATAGGACATCTCCAAGTTTGCA 1717 - 8GϾA synt R T(15)TAAAAATAGAAAATTAGAGAGTCACT 1784delG synt F T(15)AGTCAACGAGCAAGAATTTCTTTAGC 1784delG synt R T(15)ACTCCACTCAGTGTGATTCCACCTTC A559T synt F T(15)ACAAGGTGAATAACTAATTATTGGTC A559T synt R T(15)TTAAAGAAATTCTTGCTCGTTGACCT Q552X synt F T(15)TAACGAGCAAGAATTTCTTTAGCAAG Q552X synt R T(15)AACCTCCACTCAGTGTGATTCCACCT S549R(AϾC) synt F T(15)CGTGGAGGTCAACGAGCAAGAATTTC S549R(AϾC) synt R T(15)GCAGTGTGATTCTACCTTCTCCAAGA S549R(TϾG) synt F T(15)GGGAGGTCAACGAGCAAGTATTTC S549R(TϾG) synt R T(15)CCTCAGTGTGATTCCACCTTCTCCAA L558S synt F T(15)CAGCAAGGTGAATAACTAATTATTGG L558S synt R T(15)GAAGAAATTCTCGCTCGTTGACCTCC 1811 ϩ 1.6 kb AϾG synt F T(15)GTAAGTAAGGTTACTATCAATCACAC 1811 ϩ 1.6 kb AϾG synt R T(15)CATCTCAAGTACATAGGATTCTCTGT 1812 - 1GϾA synt F T(15)AAGCAGTATACAAAGATGCTGATTTG 1812 - 1GϾA synt R T(15)TTAAAAAGAAAATGGAAATTAAATTA D572N synt F T(15)AACTCTCCTTTTGGATACCTAGATGT D572N synt R T(15)TTAATAAATACAAATCAGCATCTTTG P574H synt F T(15)ATTTTGGATACCTAGATGTTTTAACA P574H synt R T(15)TGAGAGTCTAATAAATACAAATCAGC 1833delT synt F T(15)ATTGTATTTATTAGACTCTCCTTTTG 1833delT synt R T(15)CAATCAGCATCTTTGTATACTGCTCT Table 4. Continued Primer name Sense strand 5Ј 3 3Ј Name Antisense strand 5Ј 3 3Ј Y563D synt F T(15)GACAAAGATGCTGATTTGTATTTATT Y563D synt R T(15)CTACTGCTCTAAAAAGAAAATGGAAA T582R synt F T(15)GAGAAAAAGAAATATTTGAAAGGTAT T582R synt R T(15)CTTAAAACATCTAGGTATCCAAAAGG E585X synt F T(15)TAAATATTTGAAAGGTATGTTCTTTG E585X synt R T(15)ATTTTTCTGTTAAAACATCTAGGTAT 1898 ϩ 5GϾT synt F T(15)TTTCTTTGAATACCTTACTTATATTG 1898 ϩ 5GϾT synt R T(15)AATACCTTTCAAATATTTCTTTTTCT 1924del7 synt F T(15)CAGGATTTTGGTCACTTCTAAAATGG 1924del7 synt R T(15)CTGTTAGCCATCAGTTTACAGACACA 2055del9ϾA synt F T(15)ACATGGGATGTGATTCTTTCGACCAA 2055del9ϾA synt R T(15)TCTAAAGTCTGGCTGTAGATTTTGGA D648V synt F T(15)TTTCTTTCGACCAATTTAGTGCAGAA D648V synt R T(15)ACACATCCCATGAGTTTTGAGCTAAA K710X synt F T(15)TAATTTTCCATTGTGCAAAAGACTCC K710X synt R T(15)ATCGTATAGAGTTGATTGGATTGAGA I618T synt F T(15)CTTTGCATGAAGGTAGCAGCTATTTT I618T synt R T(15)GTTAATATTTTGTCAGCTTTCTTTAA R764X synt F T(15)TGAAGGAGGCAGTCTGTCCTGAACCT R764X synt R T(15)ATGCCTGAAGCGTGGGGCCAGTGCTG Q685X synt F T(15)TAATCTTTTAAACAGACTGGAGAGTT Q685X synt R T(15)ATTTTTTTGTTTCTGTCCAGGAGACA R709X synt F T(15)TGAAAATTTTCCATTGTGCAAAAGAC R709X synt R T(15)ATATAGAGTTGATTGGATTGAGAATA V754M synt F T(15)ATGATCAGCACTGGCCCCACGCTTCA V754M synt R T(15)TGCTGATGCGAGGCAGTATCGCCTCT 1949del84 synt F T(15)AAAAATCTACAGCCAGACTTTATCTC 1949del84 synt R T(15)TTTTTAGAAGTGACCAAAATCCTAGT 2108delA synt F T(15)GAATTCAATCCTAACTGAGACCTTAC 2108delA synt R T(15)ATTCTTCTTTCTGCACTAAATTGGTC 2176insC synt F T(15)CCAAAAAAACAATCTTTTAAACAGACTGGAGAG 2176insC synt R T(15)GGTTTCTGTCCAGGAGACAGGAGCAT 2184delA synt F T(15)CAAAAAACAATCTTTTAAACAGACTGG 2184delA synt R T(15)GTTTTTTGTTTCTGTCCAGGAGACAG 2105-2117 del13 synt F T(15)AAACTGAGACCTTACACCGTTTCTCA 2105-2117 del13 synt R T(15)TTTCTTTCTGCACTAAATTGGTCGAA 2307insA synt F T(15)AAAGAGGATTCTGATGAGCCTTTAGA 2307insA synt R T(15)TTTCGATGCCATTCATTTGTAAGGGA W846X synt F T(15)AAACACATACCTTCGATATATTACTGTCCAC W846X synt R T(15)TCATGTAGTCACTGCTGGTATGCTCT 2734G/AT synt F T(15)TTAATTTTTCTGGCAGAGGTAAGAAT 2734G/AT synt R T(15)TTAAGCACCAAATTAGCACAAAAATT 2766del8 synt F T(15)GGTGGCTCCTTGGAAAGTGAGTATTC 2766del8 synt R T(15)CACCAAAGAAGCAGCCACCTGGAATGG 2790 - 2AϾG synt F T(15)GGCACTCCTCTTCAAGACAAAGGGAA 2790 - 2AϾG synt R T(15)CGTAAAGCAAATAGGAAATCGTTAAT 2991del32 synt F T(15)TTCAACACGTCGAAAGCAGGTACTTT 2991del32 synt R T(15)AAACATTTTGTGGTGTAAAATTTTCG Q890X synt F T(15)TAAGACAAAGGGAATAGTACTCATAG Q890X synt R T(15)AAAGAGGAGTGCTGTAAAGCAAATAG 2869insG synt F T(15)GATTATGTGTTTTACATTTACGTGGG 2869insG synt R T(15)CACGAACTGGTGCTGGTGATAATCAC 3120GϾA synt F T(15)AGTATGTAAAAATAAGTACCGTTAAG 3120GϾA synt R T(15)TTGGATGAAGTCAAATATGGTAAGAG 3121 - 2AϾT synt F T(15)TGTTGTTATTAATTGTGATTGGAGCT 3121 - 2AϾT synt R T(15)AGTAAGATCAAAGAAAACATGTTGGT 3132delTG synt F T(15)TTGATTGGAGCCATAGCAGTTGTCGC 3132delTG synt R T(15)AATTAATAACAACTGTAAGATCAAAG 3271delGG synt F T(15)ATATGACAGTGAATGTGCGATACTCA 3271delGG synt R T(15)ATTCAGATTCCAGTTGTTTGAGTTGC 3171delC synt F T(15)ACCTACATCTTTGTTGCAACAGTGCC 3171delC synt R T(15)AGGTTGTAAAACTGCGACAACTGCTA 3171insC synt F T(15)CCCCTACATCTTTGTTGCTACAGTGC 3171insC synt R T(15)GGGGTTGTAAAACTGCGACAACTGCT 3199del6 synt F T(15)GAGTGGCTTTTATTATGTTGAGAGCATAT 3199del6 synt R T(15)CCACTGGCACTGTTGCAACAAAGATG M1101K synt F T(15)AGAGAATAGAAATGATTTTTGTCATC M1101K synt R T(15)TTTTGGAACCAGCGCAGTGTTGACAG G1061R synt F T(15)CGACTATGGACACTTCGTGCCTTCGG G1061R synt R T(15)GTTTTAAGCTTGTAACAAGATGAGTG R1066L synt F T(15)TTGCCTTCGGACGGCAGCCTTACTTT R1066L synt R T(15)AGAAGTGTCCATAGTCCTTTTAAGCT R1070P synt F T(15)CGCAGCCTTACTTTGAAACTCTGTTC R1070P synt R T(15)GGTCCGAAGGCACGAAGTGTCCATAG L1077P synt F T(15)CGTTCCACAAAGCTCTGAATTTACAT L1077P synt R T(15)GGAGTTTCAAAGTAAGGCTGCCGTCC W1089X synt F T(15)AGTTCTTGTACCTGTCAACACTGCGC W1089X synt R T(15)TAGTTGGCAGTATGTAAATTCAGAGC L1093P synt F T(15)CGTCAACACTGCGCTGGTTCCAAATG L1093P synt R T(15)GGGTACAAGAACCAGTTGGCAGTATG W1098R synt F T(15)CGGTTCCAAATGAGAATAGAAATGAT W1098R synt R T(15)GGCGCAGTGTTGACAGGTACAAGAAC Q1100P synt F T(15)CAATGAGAATAGAAATGATTTTTGTC Q1100P synt R T(15)GGGAACCAGCGCAGTGTTGACAGGTA D1152H synt F T(15)CATGTGGATAGCTTGGTAAGTCTTAT D1152H synt R T(15)GTATGCTGGAGTTTACAGCCCACTGC R1158X synt F T(15)TGATCTGTGAGCCGAGTCTTTAAGTT R1158X synt R T(15)ACATCTGAAATAAAAATAACAACATT S1196X synt F T(15)GACACGTGAAGAAAGATGACATCTGG S1196X synt R T(15)CAATTCTCAATAATCATAACTTTCGA 3732delA synt F T(15)GGAGATGACATCTGGCCCTCAGGGGG 3732delA synt R T(15)CTCCTTCACGTGTGAATTCTCAATAA 3791delC synt F T(15)AAGAAGGTGGAAATGCCATATTAGAG 3791delC synt R T(15)TTGTATTTTGCTGTGAGATCTTTGAC 3821delT synt F T(15)ATTCCTTCTCAATAAGTCCTGGCCAG 3821delT synt R T(15)GAATGTTCTCTAATATGGCATTTCCA Q1238X synt F T(15)TAGAGGGTGAGATTTGAACACTGCTT Q1238X synt R T(15)AGCCAGGACTTATTGAGAAGGAAATG S1255X (ex19)synt F T(15)GTCTGGCCCTCAGGGGGCCAAATGAC S1255X (ex19) synt R T(15)CGTCATCTTTCTTCACGTGTGAATTC S1255X;L synt F T(15)AAGCTTTTTTGAGACTACTGAACACT S1255X;L synt R T(15)TATAACAAAGTAATCTTCCCTGATCC 3849 ϩ 4AϾG synt F T(15)GGATTTGAACACTGCTTGCTTTGTTA 3849 ϩ 4AϾG synt R T(15)CCACCCTCTGGCCAGGACTTATTGAG 3850 - 1GϾA synt F T(15)AGTGGGCCTCTTGGGAAGAACTGGAT 3850 - 1GϾA synt R T(15)TTATAAGGTAAAAGTGATGGGATCAC 3905insT synt F T(15)TTTTTTTGAGACTACTGAACACTGAA 3905insT synt R T(15)AAAAAAAGCTGATAACAAAGTACTCT 3876delA synt F T(15)CGGGAAGAGTACTTTGTTATCAGCTT 3876delA synt R T(15)CGATCCAGTTCTTCCCAAGAGGCCCA G1244V synt F T(15)TAAGAACTGGATCAGGGAAGAGTACT G1244V synt R T(15)ACCAAGAGGCCCACCTATAAGGTAAA G1249E synt F T(15)AGAAGAGTACTTTGTTATCAGCTTTT G1249E synt R T(15)TCTGATCCAGTTCTTCCCAAGAGGCC S1251N synt F T(15)ATACTTTGTTATCAGCTTTTTTGAGACTACTG S1251N synt R T(15)TTCTTCCCTGATCCAGTTCTTCCCAA S1252P synt F T(15)CCTTTGTTATCAGCTTTTTTGAGACT S1252P synt R T(15)GACTCTTCCCTGATCCAGTTCTTCCC D1270N synt F T(15)AATGGTGTGTCTTGGGATTCAATAAC D1270N synt R T(15)TGATCTGGATTTCTCCTTCAGTGTTC W1282R synt F T(15)CGGAGGAAAGCCTTTGGAGTGATACC W1282R synt R T(15)GCTGTTGCAAAGTTATTGAATCCCAA R1283K synt F T(15)AGAAAGCCTTTGGAGTGATACCACAG R1283K synt R T(15)TTCCACTGTTGCAAAGTTATTGAATC 4005 ϩ 1GϾA synt F T(15)ATGAGCAAAAGGACTTAGCCAGAAAA 4005 ϩ 1GϾA synt R T(15)TCTGTGGTATCACTCCAAAGGCTTTC 4010del4 synt F T(15)GTATTTTTTCTGGAACATTTAGAAAAAACTTGG 4010del4 synt R T(15)AAAATACTTTCTATAGCAAAAAAGAAAAGAAGAA 4016insT synt F T(15)TTTTTTTCTGGAACATTTAGAAAAAACTTGG 4016insT synt R T(15)AAAAAAATAAATACTTTCTATAGCAAAAAAGAAAAGAAGA CFTRdele21 synt F T(15)TAGGTAAGGCTGCTAACTGAAATGAT CFTRdele21 synt R T(15)CCTATAGCAAAAAAGAAAAGAAGAAGAAAGTATG 4382delA synt F T(15)GAGAGAACAAAGTGCGGCAGTACGAT 4382delA synt R T(15)CTCTATGACCTATGGAAATGGCTGTT Bold, mutation allele of interest; bold and italicized, modified nucleotide. 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[hide] Characteristic multiorgan pathology of cystic fibr... Am J Pathol. 2004 Apr;164(4):1481-93. Durie PR, Kent G, Phillips MJ, Ackerley CA
Characteristic multiorgan pathology of cystic fibrosis in a long-living cystic fibrosis transmembrane regulator knockout murine model.
Am J Pathol. 2004 Apr;164(4):1481-93., [PMID:15039235]

Abstract [show]
The lack of an appropriate animal model with multiorgan pathology characteristic of the human form of cystic fibrosis has hampered our understanding of the pathobiology of the disease. We evaluated multiple organs of congenic C57BL/6J cystic fibrosis transmembrane regulator (Cftr)(-/-) and Cftr(+/+) mice maintained from weaning on a liquid diet then sacrificed between 1 and 24 months of age. The lungs of the Cftr(-/-) animals showed patchy alveolar overdistention, interstitial thickening, and fibrosis, with progression up to 6 months of age. The proximal and distal airway surface was encased with mucus-like material but lacked overt evidence of chronic bacterial infections or inflammation. All Cftr(-/-) animals showed progressive liver disease, with hepatosteatosis, focal cholangitis, inspissated secretions, and bile duct proliferation; after 1 year of age there was progression to focal biliary cirrhosis. The intercalated, intralobular and interlobular ducts and acinar lumina of the exocrine pancreas, the parotid and submaxillary glands of the Cftr(-/-) animals were dilated and filled with inspissated material, as well as mild inflammation and acinar cell drop out. Quantitative measurements of the pancreas showed significant acinar atrophy and increased acinar volume in comparison with age-matched Cftr(+/+) littermates. The ileal lumen and crypts were filled with adherent fibrillar material. After 3 months of age the vas deferens of the Cftr(-/-) animals could not be identified. None of the aforementioned pathological changes were observed in the Cftr(+/+) littermates fed the same liquid diet. We show, for the first time, that long-lived C578L/6J Cftr(-/-) mice develop manifestations of cystic fibrosis-like disease in all pathologically affected organs in the human form of cystic fibrosis.

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303 Dickinson P: Generation of a CF mutant mouse possessing the G480C mutation. Login to comment

[hide] Cystic fibrosis and related diseases of the pancre... Best Pract Res Clin Gastroenterol. 2002 Jun;16(3):511-26. Naruse S, Kitagawa M, Ishiguro H, Fujiki K, Hayakawa T
Cystic fibrosis and related diseases of the pancreas.
Best Pract Res Clin Gastroenterol. 2002 Jun;16(3):511-26., [PMID:12079272]

Abstract [show]
The discovery of the gene for cystic fibrosis (CF), the cystic fibrosis transmembrane conductance regulator (CFTR), brought about a new era in the study of this disease. Identification of the molecular target has yielded a flood of data that add to our understanding of the pathogenesis, diagnosis and treatment of CF. The CFTR protein is a cAMP-regulated Cl(-) channel with multiple functions in epithelial cells. In the exocrine pancreas the CFTR plays a key role in the apical Cl(-), HCO(3)(-), and water transport in duct cells. The severe loss of functions, caused by mutations of the CFTR gene, leads to pathological lesions of the pancreas. Over 1200 CFTR mutations and polymorphisms have been identified and their diversity may explain the high level of heterogeneity in the CF phenotype. Mutation analyses of the CFTR gene have revealed a spectrum of CFTR-related diseases that do not fit the classical CF picture but are associated with dysfunction of CFTR, such as chronic pancreatitis.

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62 is observed only when normal CFTR function is less than 1%.13 In general, patients with pancreatic insuciency are homozygous or compound heterozygous for two severe mutations (class I, II or III in Figure 3), such as DF508, DI507, Q493X, G542X, R553X, W1282X, 621 1G 4 T, 1717-1G 4 A, 556delA, 3659delC, I148T, G480C, V520F, G551D, and R560T, whereas the PS phenotype occurs in patients who have one or two mild CFTR mutations, such as R117H, R334W, R347P, A455E, and P574H (class IV or V).5,20 EXOCRINE PANCREAS IN CYSTIC FIBROSIS Pathology of the pancreas in CF There is a spectrum of pancreatic abnormalities in CF irrespective of age.21,22 Pancreatic lesions may be absent in an individual case, but in long-standing CF the pancreas is small, hard and nodular with increased fat and multiple cysts; hence the name `cystic ®brosis of the pancreas'. Login to comment
64 is observed only when normal CFTR function is less than 1%.13 In general, patients with pancreatic insuQciency are homozygous or compound heterozygous for two severe mutations (class I, II or III in Figure 3), such as DF508, DI507, Q493X, G542X, R553X, W1282X, 621 W 1G 4 T, 1717-1G 4 A, 556delA, 3659delC, I148T, G480C, V520F, G551D, and R560T, whereas the PS phenotype occurs in patients who have one or two mild CFTR mutations, such as R117H, R334W, R347P, A455E, and P574H (class IV or V).5,20 EXOCRINE PANCREAS IN CYSTIC FIBROSIS Pathology of the pancreas in CF There is a spectrum of pancreatic abnormalities in CF irrespective of age.21,22 Pancreatic lesions may be absent in an individual case, but in long-standing CF the pancreas is small, hard and nodular with increased fat and multiple cysts; hence the name `cystic &#ae;brosis of the pancreas'. Login to comment

[hide] Modeling of nucleotide binding domains of ABC tran... J Bioenerg Biomembr. 1997 Oct;29(5):503-24. Bianchet MA, Ko YH, Amzel LM, Pedersen PL
Modeling of nucleotide binding domains of ABC transporter proteins based on a F1-ATPase/recA topology: structural model of the nucleotide binding domains of the cystic fibrosis transmembrane conductance regulator (CFTR).
J Bioenerg Biomembr. 1997 Oct;29(5):503-24., [PMID:9511935]

Abstract [show]
Members of the ABC transporter superfamily contain two nucleotide binding domains. To date, the three dimensional structure of no member of this super-family has been elucidated. To gain structural insight, the known structures of several other nucleotides binding proteins can be used as a framework for modeling these domains. We have modeled both nucleotide binding domains of the protein CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) using the two similar domains of mitochondrial F1-ATPase. The models obtained, provide useful insights into the putative functions of these domains and their possible interaction as well as a rationale for the basis of Cystic Fibrosis causing mutations. First, the two nucleotide binding domains (folds) of CFTR are each predicted to span a 240-250 amino acid sequence rather than the 150-160 amino acid sequence originally proposed. Second, the first nucleotide binding fold, is predicted to catalyze significant rates of ATP hydrolysis as a catalytic base (E504) resides near the y phosphate of ATP. This prediction has been verified experimentally [Ko, Y.H., and Pedersen, P.L. (1995) J. Biol. Chem. 268, 24330-24338], providing support for the model. In contrast, the second nucleotide binding fold is predicted at best to be a weak ATPase as the glutamic acid residue is replaced with a glutamine. Third, F508, which when deleted causes approximately 70% of all cases of cystic fibrosis, is predicted to lie in a cleft near the nucleotide binding pocket. All other disease causing mutations within the two nucleotide binding domains of CFTR either reside near the Walker A and Walker B consensus motifs in the heart of the nucleotide binding pocket, or in the C motif which lies outside but near the nucleotide binding pocket. Finally, the two nucleotide binding domains of CFTR are predicted to interact, and in one of the two predicted orientations, F508 resides near the interface. This is the first report where both nucleotide binding domains of an ABC transporter and their putative domain-domain interactions have been modeled in three dimensions. The methods and the template used in this work can be used to analyze the structures and function of the nucleotide binding domains of all other members of the ABC transporter super-family.

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360 The CFTR NBD1 model that results (Fig. 6) gathers the disease causing mutations in three different clusters: (1) mutations affecting the nucleotide binding pocket and the putative general base: A455E, G458V, E504Q AI507 AF508 P574H; (2) mutations in motif C which are probably related to an interaction with region D: S549[R,N,I] G551[S,D], R553Q; and (3) mutations within or near motif B, L558S, A559T, R560T, Y563N and mutations S492F and G480C. Login to comment

[hide] Identification of common cystic fibrosis mutations... Am J Hum Genet. 1997 May;60(5):1122-7. Macek M Jr, Mackova A, Hamosh A, Hilman BC, Selden RF, Lucotte G, Friedman KJ, Knowles MR, Rosenstein BJ, Cutting GR
Identification of common cystic fibrosis mutations in African-Americans with cystic fibrosis increases the detection rate to 75%.
Am J Hum Genet. 1997 May;60(5):1122-7., [PMID:9150159]

Abstract [show]
Cystic fibrosis (CF)--an autosomal recessive disorder caused by mutations in CF transmembrane conductance regulator (CFTR) and characterized by abnormal chloride conduction across epithelial membranes, leading to chronic lung and exocrine pancreatic disease--is less common in African-Americans than in Caucasians. No large-scale studies of mutation identification and screening in African-American CF patients have been reported, to date. In this study, the entire coding and flanking intronic sequence of the CFTR gene was analyzed by denaturing gradient-gel electrophoresis and sequencing in an index group of 82 African-American CF chromosomes to identify mutations. One novel mutation, 3120+1G-->A, occurred with a frequency of 12.3% and was also detected in a native African patient. To establish frequencies, an additional group of 66 African-American CF chromosomes were screened for mutations identified in two or more African-American patients. Screening for 16 "common Caucasian" mutations identified 52% of CF alleles in African-Americans, while screening for 8 "common African" mutations accounted for an additional 23%. The combined detection rate of 75% was comparable to the sensitivity of mutation analysis in Caucasian CF patients. These results indicate that African-Americans have their own set of "common" CF mutations that originate from the native African population. Inclusion of these "common" mutations substantially improves CF mutation detection rates in African-Americans.

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45 In the two independent African-American groups, samples were screened for eight mutations that have been identified in two or more African-American CF patients, including 405+3A-+C (present study), 444delA (White et al. 1991), G480C (Smit et al. 1995), R553X (Cutting et al. 1990b), A559T (Cutting et al. 1990b), 2307insA (Smit et al. 1993), 3120+1G-+A (present study), and S1255X (Cutting et al. Login to comment
47 Screening protocols for mutations 444delA, G480C, 2307insA, and S1255X were previously reported in the references cited in the preceding sentence. Login to comment
48 The A559T mutation creates a unique MseI restriction site. Login to comment
70 Finally, 13 mutations found in one patient each had been previously reported in Caucasian patients (Q98R, R352Q, V520F, 1812-1G--A, G542X, S549N, and Y913C) (Romey et al. 1995; Welsh et al. 1995) or in African-American patients (444delA, G480C, 1342-2delAG [originally reported as 1342-1G--+C], 2307insA, 3662delA, and W1316X) (Cutting et al. 1990b; White et al. 1991; Zielenski et al. Login to comment
86 The most common muta- Table 2 Distribution of CF Mutations in African-American and U.S.-Caucasian CF Patients African-American U.S. Caucasiana Mutation (n= 148) % (n = 8,714) % Caucasian mutations: AF508 71 48 5,769 66.2 R117H 0 0 47 .5 621+1 G--T 0 0 68 .8 R334W 1 .7 7 .1 R347P 0 0 24 .3 A455E 0 0 5 .1 AI507 1 .7 10 .1 1717-1 G-IA 1 .7 39 .5 G542X 1 .7 204 2.3 S549N 1 .7 4 .1 GS51D 1 .7 173 2.0 R553X (Caucasian)b 0 0 87 1.0 R560T 0 0 16 .2 3849+10kb C-T 0 0 51 .6 W1282X 0 0 235 2.7 N1303K 0 0 116 1.3 Subtotal 77 52 6,855 78.7 African-American mutations: 405+3 A-C 2 1.4 ... ... 444delA 1 .7 ... ... G480C 2 1.4 ... ... R553X (African)b 3 2.0 ... ... A559T 3 2.0 ... ... 2307insA 3 2.0 ... ... 3120+1 GC-A 18 12.2 ... ... S1255X 2 1.4 ... ... Subtotal 34 23 ... ... Total 111 75.0 6,855 78.7 NOTE.-Percentages are rounded. Login to comment
46 In the two independent African-American groups, samples were screened for eight mutations that have been identified in two or more African-American CF patients, including 405+3A-+C (present study), 444delA (White et al. 1991), G480C (Smit et al. 1995), R553X (Cutting et al. 1990b), A559T (Cutting et al. 1990b), 2307insA (Smit et al. 1993), 3120+1G-+A (present study), and S1255X (Cutting et al. Login to comment
71 Finally, 13 mutations found in one patient each had been previously reported in Caucasian patients (Q98R, R352Q, V520F, 1812-1G--A, G542X, S549N, and Y913C) (Romey et al. 1995; Welsh et al. 1995) or in African-American patients (444delA, G480C, 1342-2delAG [originally reported as 1342-1G--+C], 2307insA, 3662delA, and W1316X) (Cutting et al. 1990b; White et al. 1991; Zielenski et al. Login to comment
87 The most common muta- Table 2 Distribution of CF Mutations in African-American and U.S.-Caucasian CF Patients African-American U.S. Caucasiana Mutation (n= 148) % (n = 8,714) % Caucasian mutations: AF508 71 48 5,769 66.2 R117H 0 0 47 .5 621+1 G--T 0 0 68 .8 R334W 1 .7 7 .1 R347P 0 0 24 .3 A455E 0 0 5 .1 AI507 1 .7 10 .1 1717-1 G-IA 1 .7 39 .5 G542X 1 .7 204 2.3 S549N 1 .7 4 .1 GS51D 1 .7 173 2.0 R553X (Caucasian)b 0 0 87 1.0 R560T 0 0 16 .2 3849+10kb C-T 0 0 51 .6 W1282X 0 0 235 2.7 N1303K 0 0 116 1.3 Subtotal 77 52 6,855 78.7 African-American mutations: 405+3 A-C 2 1.4 ... ... 444delA 1 .7 ... ... G480C 2 1.4 ... ... R553X (African)b 3 2.0 ... ... A559T 3 2.0 ... ... 2307insA 3 2.0 ... ... 3120+1 GC-A 18 12.2 ... ... S1255X 2 1.4 ... ... Subtotal 34 23 ... ... Total 111 75.0 6,855 78.7 NOTE.-Percentages are rounded. Login to comment

[hide] Cystic fibrosis mutation detection by hybridizatio... Hum Mutat. 1996;7(3):244-55. Cronin MT, Fucini RV, Kim SM, Masino RS, Wespi RM, Miyada CG
Cystic fibrosis mutation detection by hybridization to light-generated DNA probe arrays.
Hum Mutat. 1996;7(3):244-55., [PMID:8829658]

Abstract [show]
We have combined photochemistry and photolithography with solid-phase DNA synthesis chemistry to form a new technology that makes high density oligonucleotide probe array synthesis possible. Hybridization to these two-dimensional arrays containing hundreds or thousands of oligonucleotide probes provides a powerful DNA sequence analysis tool. Two types of light-generated DNA probe arrays have been used to test for a variety of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. One array, made up of 428 probes, was designed to scan through the length of CFTR exon 11 and identify differences from the wild type reference sequence. The second type of array contained 1480 probes chosen to detect known deletions, insertions, or base substitution mutations. The validity of the probe arrays was established by hybridizing them with fluorescently labeled control oligonucleotide targets. Characterized mutant CFTR genomic DNA samples were then used to further test probe array hybridization specificity. Finally, ten unknown patient samples were genotyped using the CFTR probe array assay. The genotype assignments were identical to those obtained by PCR product restriction fragment analysis. Our results show that light-generated DNA probe arrays are highly effective in analyzing complex mutation and polymorphism patterns in a relatively large gene such as CFTR.

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155 One sample was compound heterozygous for G480C (G+T) in exon 10and G551D (G-A) in AL. n-2 n-1 n n+l n+2 A GGTCWCGAGCAAG GGTCAATGAGCAAG AGGTCAACGAGCAAG GGTCAATGAGCAAG GGTCAACGAGCAAG GGTCWTGAGCAAG - GGTCUTGAGCAAG GGTCAAZGAGCAAG GGTCAACGAGCAAG GGTCAACGAGCAAG GGTCAAZGAGCAAG B C D FIGURE 3. Login to comment
175 In Figure 4A, probe sets specific for the G480C and G551D mutations are indicated along with diagrams showing the expected heterozygote hybridization patterns. Login to comment
178 All of these probes sets, except for G480C and G551D, give complete homozygous wild type hybridization patterns. Login to comment
180 In particular, there is hybridization with the C probes in the "n" position of the G480C array. Login to comment
212 A Image of the specialized mutation specific array hybridizedwith exon 10and exon 11targets multiplexedfrom acompoundheterozygous genomic DNAsample with G551D and G480C mutations. Login to comment
213 Diagrams of the G551D and G480C mutation subarrays indicating probes fully complementaryto the wild-type and mutant sequences are at the sides of the image. Login to comment
217 G480C 5'TCAGAGTGTAAAAT3`. Login to comment
219 A total of 15of the 37 mutation-specific probe sets hybridize with exon 10and exon 11targets (Table 1).All except G551D and G480C display wild-type hybridization patterns. Other hybridization signals that do not form complete patterns (as compared with examples in Fig. 3)result from cross-hybridization with probes that are partially complementary to the target. Login to comment
238 Cystic Fibrosis Mutation-Specific DNA Probe Array" Mutation Exon and column Tested Subarrayhow G85E R117H I148T 621 -+ l(G+T) 711 + 1(G+T) R334W R347H R347P 1078 delT A455E G480C Q493X A1507 F508C AF508 V520F G542X S549R(T-+ G) G551D Q552X R553X A559T R560T 1898 + l(G-,A) 2184 del A 2789 + 5(G+ A) R1066C L1077P Y1092X R1162X 3659 del C 1717-1(& A) 3272 - 26(A+ G) 3 4 4 in 4 in 5 7 7 7 7 9 10 10 10 10 10 10 in 10 11 11 11 11 11 11 11 in 12 13 in 14b in 17a 17b 17b 17b 19 19 * * * * * * * * * * * * * * * * * * * * * * * * * * * * 3849 + lOkb C-, T in 19 9,3 W1282X 20 994 3905insT 20 10.1 * N1303K 21 10,2 * * * "Row and column locations for each of the mutation specific,40 probe sets included in the specialized probe array design. Login to comment

[hide] Missense mutation (G480C) in the CFTR gene associa... Hum Mol Genet. 1995 Feb;4(2):269-73. Smit LS, Strong TV, Wilkinson DJ, Macek M Jr, Mansoura MK, Wood DL, Cole JL, Cutting GR, Cohn JA, Dawson DC, et al.
Missense mutation (G480C) in the CFTR gene associated with protein mislocalization but normal chloride channel activity.
Hum Mol Genet. 1995 Feb;4(2):269-73., [PMID:7757078]

Abstract [show]
We have identified a novel CFTR missense mutation associated with a protein trafficking defect in mammalian cells but normal chloride channel properties in a Xenopus oocyte assay. The mutation, a cysteine for glycine substitution at residue 480 (G480C), was detected in a pancreatic insufficient, African-American, cystic fibrosis (CF) patient. G480C was found on one additional CF chromosome and on none of 220 normal chromosomes, including 160 chromosomes from normal African-American individuals. Western blot analysis and immunofluorescence studies revealed that, in 293T cells, the encoded mutant protein was not fully glycosylated and failed to reach the plasma membrane, suggesting that the G480C protein was subject to defective intracellular processing. However, in Xenopus oocytes, a system in which mutant CFTR proteins are less likely to experience an intracellular processing/trafficking deficit, expression of G480C CFTR was associated with a chloride conductance that exhibited a sensitivity to activation by forskolin and 3-isobutyl-1-methylxanthine (IBMX) that was similar to that of wild-type CFTR. This appears to be the first identification of a CFTR mutant with a single amino acid substitution in which the sole basis for disease is mislocalization of the protein.

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3 The mutation, a cystelne for glycine substitution at residue 480 (G480C), was detected in a pancreatic insufficient, African-American, cystic fibrosis (CF) patient. Login to comment
4 G480C was found on one additional CF chromosome and on none of 220 normal chromosomes, including 160 chromosomes from normal African-American individuals. Login to comment
5 Western blot analysis and immunofluorescence studies revealed that, in 293T cells, the encoded mutant protein was not fully glycosylated and failed to reach the plasma membrane, suggesting that the G480C protein was subject to defective Intracellular processing. Login to comment
6 However, in Xenopus oocytes, a system in which mutant CFTR proteins are less likely to experience an intracellular processing/trafficking deficit, expression of G480C CFTR was associated with a chloride conductance that exhibited a sensitivity to activation by forskolin and 3-isobutyl-1-methylxanthine (IBMX) that was similar to that of wild-type CFTR. Login to comment
25 In this report we describe a glycine to cysteine substitution at amino acid 480 (G480C), which is associated with a mislocalized protein in mammalian cells cultured at 37°C but *To whom correspondence should be addressed at present address: Department of Physiology, University of Michigan, Ann Arbor, MI 48109-0622, USA + To whom reprint requests should be addressed at present address: National Center for Human Genome Research, National Institutes of Health, Building 38A, Room 605, Bethesda, MD 20892, USA exhibits sensitivity to activation by cAMP in Xenopus ooyctes at 19°C similar to that of wild-type CFTR. Login to comment
29 The sequence revealed a G to T transversion at nucleotide 1570 (Fig. IB), creating a glycine to cysteine missense mutation at residue 480 (G480C). Login to comment
32 The G480C mutation was detected in a second African-American CF patient by denaturing gradient gel electrophoresis and confirmed by sequencing. Login to comment
35 G480C was detected in one additional non-AF508 CF chromosome of 378 tested. Login to comment
36 This additional G480C patient has a Caucasian father and an African-American mother. Login to comment
37 It could not be determined which parent carries the G480C mutation, as parental DNA was not available. Login to comment
38 The three patients bearing the G480C mutation were not known to be related. Login to comment
40 Immunoblot analysis and localization of G480C CFTR The effect of the G480C mutation on the processing of the CFTR protein was investigated by means of Western blot analysis and immunofluorescence. Login to comment
41 293T cells, which lack detectable endogenous CFTR (15), were transfected with wild-type, AF508 or G480C CFTR cDNA expression vectors. Login to comment
43 Only the incompletely glycosylated form of CFTR was observed in cells transfected with AF5O8 or G480C cDNA. Login to comment
44 Even upon longer exposures, there was no detectable signal for mature CFTR in the AF508 and G480C lysates. Login to comment
45 This suggests that G480C CFTR, like AF508, is not processed to the mature, fully glycosylated form of CFTR in the cell. Login to comment
48 Both AF508, a known trafficking mutant (Fig. 3B) and G480C (Fig. 3C) CFTR were associated with staining that was restricted to the cytoplasm, consistent with the classification of G480C as a trafficking mutation. Login to comment
49 Functional analysis of G480C in Xenopus oocytes Membrane currents were recorded from Xenopus oocytes injected with RNA transcribed from either wild-type or G480C constructs. Login to comment
53 In contrast, in oocytes injected with RNA coding for G480C CFTR the Ki/2 for activation of Cl" conductance was identical to that for wild-type CFTR (Fig. 4). Login to comment
55 DISCUSSION The identification of G480C in three CF chromosomes, including two apparently independent, unrelated African-American CF chromosomes, but not in any normal chromosomes (includ- Sllbp -2»lbp Figure 1. Login to comment
56 Detection of G480C by chemical mismatch cleavage and DNA sequence analysis. Login to comment
58 Lanes 1 and 2 show DNA from patients with no mutations in exon 10 and lane 3 shows DNA from a patient with the G480C mutation. Login to comment
59 (B) Nucleotide sequence of a portion of exon 10 from the patient bearing the G480C mutation. Login to comment
64 Lane 1, mock transfected; lane 2, wild-type transfected; lane 3, AF508 transfected; lane 4, G480C transfected; lane 5, T84. Login to comment
67 ing 160 African-American normal chromosomes) is consistent with the classification of G480C as a disease causing mutation, rather than a neutral polymorphism. Login to comment
70 The identification of G480C mutation in at least two African-American CF chromosomes suggests that G480C may represent a common CF mutation in the African-American population. Login to comment
73 The results described here suggest that G480C CFTR, like AF508 CFTR, is misprocessed in the cell. Login to comment
74 The functional properties of G480C CFTR were examined in Xenopus oocytes. Login to comment
75 While expression of G480C CFTR in Xenopus oocytes is not equivalent to expression in mammalian cells at a permissive temperature, previous studies have shown that mutant CFTR proteins are less likely to be subject to intracellular trafficking problems when expressed in oocytes (11,12). Login to comment
78 In contrast, dose-dependent activation of G480C in oocytes indicates that in this system, G480C CFTR functions identically to wild type. Login to comment
80 G480C is not located in a region of the protein expected to form the conducting pore, rather it is located in the first NBF where other mutations have not proven to affect single channel conductance (13). Login to comment
81 If indeed G480C is associated with functional properties that are identical to wild-type CFTR at temperatures permissive for normal trafficking, it is the first example of a CF missense Figure 3. Login to comment
82 Localization of wild-type, AF508, and G480C CFTR by fluorescence miscroscopy. Login to comment
85 IBMX dose-response relationships for wild-type and G480C CFTR. Login to comment

[hide] Cystic fibrosis: genotypic and phenotypic variatio... Annu Rev Genet. 1995;29:777-807. Zielenski J, Tsui LC
Cystic fibrosis: genotypic and phenotypic variations.
Annu Rev Genet. 1995;29:777-807., [PMID:8825494]

Abstract [show]
Cystic fibrosis (CF) is a common genetic disorder in the Caucasian population. The gene was identified in 1989 on the basis of its map location on chromosome 7. The encoded gene product, named cystic fibrosis transmembrane conductance regulator (CFTR), corresponds to a cAMP-regulated chloride channel found almost exclusively in the secretory epithelial cells. Although the major mutation that results in a single amino acid deletion (F508) accounts for 70% of the disease alleles, more than 550 additional mutant alleles of different forms have been detected. Many of these mutations can be divided into five general classes in terms of their demonstrated or presumed molecular consequences. In addition, a good correlation has been found between CFTR genotype and one of the clinical variables--pancreatic function status. An unexpected finding, however, is the documentation of CFTR mutations in patients with atypical CF disease presentations, including congenital absence of vas deferens and several pulmonary diseases. Thus, the implication of CFTR mutation is more profound than CF alone.

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629 FrnROSIS mutations of this class, such as G480C, which also appear to have appreciable cAMP-responsive chloride channel activity after reaching the plasma membrane (163). Login to comment

[hide] Mutation analysis in 600 French cystic fibrosis pa... J Med Genet. 1994 Jul;31(7):541-4. Chevalier-Porst F, Bonardot AM, Gilly R, Chazalette JP, Mathieu M, Bozon D
Mutation analysis in 600 French cystic fibrosis patients.
J Med Genet. 1994 Jul;31(7):541-4., [PMID:7525963]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) gene of 600 unrelated cystic fibrosis (CF) patients living in France (excluding Brittany) was screened for 105 different mutations. This analysis resulted in the identification of 86% of the CF alleles and complete genotyping of 76% of the patients. The most frequent mutations in this population after delta F508 (69% of the CF chromosomes) are G542X (3.3%), N1303K (1.8%), W1282X (1.5%), 1717-1G-->A (1.3%), 2184delA + 2183 A-->G (0.9%), and R553X (0.8%).

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21 Among the 104 other CFTR mutations tested on the 373 non-AF508 CF chromosomes, none of the following 58 mutations were found: G91R, 435 insA, 444delA, D11OH, 556delA, 557delT, R297Q, 1154insTC, R347L, R352Q, Q359K/T360K, 1221delCT, G480C, Q493R, V520F, C524X, 1706dell7, S549R (A-C), S549N, S549I, G551S, 1784delG, Q552X, L558S, A559T, R560T, R560K, Y563N, P574H, 2307insA, 2522insC, 2556insAT, E827X, Q890X, Y913C, 2991de132 (Dork et al, personal communication), L967S, 3320ins5, 3359delCT, H1085R, R1158X, 3662delA, 3667del4, 3667ins4, 3732delA, 3737delA, W1204X, 3750delAG, I 1234V, Q1238X, 3850- 3T-+G, 3860ins31, S1255X, 3898insC, D1270N, R1283M, F1286S, 4005 + I G-A. Forty-six other mutations were found on at Distribution of CFTR mutations found in our sample ofpopulation (1200 CF chromosomes) Mutations tested No of CF chromosomes Haplotypes Method with the mutation XV2C-KM19 (% of total CF alleles) Exon 3: G85E 4 (033) 3C HinfI/ASO394delTT 2 2B PAGEExon 4: R117H 1 B ASOY122X 2 2C MseI/sequenceI148T 1 B ASO621+IG-J* 1 B MseIIASOExon 5: 711+1G--T 8(07) 8A ASOExon 7: AF311 1 C PAGE/sequencelO78delT 5 (0-42) 5C PAGE/ASOR334W 5 (0-42) 2A,2C,ID MspIlASOR347P 5 (042) 5A CfoI/NcoIR347H 1 Cfol/sequenceExon 9: A455E 1 B ASOExon 10: S492F I C DdeI/sequenceQ493X 1 D ASOl609deICA 1 C PAGE/Ddel/sequenceA1507 3 (025) 3D PAGE/ASOAF508 827 (69) 794B,30D,2C,IA PAGEl677delTA 1 A PAGE/sequenceExon I11: 1717-IG--.A 16(1-3) 14B Modified primers + AvaIIG542X 40 (3-3) 29B,5D,2A Modified primers + BstNiS549R(T--*G) 2 2B ASOG551D 3 (025) 3B HincII/Sau3AR553X 10(0-8) 6A,1B,2C,ID Hincll/sequenceExon 12: 1898+IG--A 1 C ASO1898+ IG-C 2 IC ASOExon 13: l9l8deIGC 1 A PAGE/sequence1949de184 I C PAGE/sequenceG628R(G-+A) 2 2A Sequence2118de14 I c PAGE/sequence2143de1T 1 B PAGE/modified primers2184de1A+2183A--*G 11 (0-9) lIB PAGE/ASO2184de1A 1 ASOK710X 3 (025) IC XmnI2372de18 1 B PAGE/sequenceExon 15: S945L 1 C TaqlExon 17b:L1065P I MnlIL1077P 1 A ASOY1092X 3 (025) 2C,IA Rsal/ASOExon 19: RI1162X 6 (0-5) 5C,IA DdeI/ASO3659delC 3 (025) 3C ASOExon 20: G1244E 2 2A MboIIS1251N 2 2C RsaI3905insT 4 (0-33) 4C PAGE/ASOW1282X 18 (105) 15B,1D MnlI/ASOR1283K 1 C Mnll/sequenceExon 21: N1303K 22 (1-8) 18B,lA,ID Modified primers+BstNI 47 mutations 1031 (85 9) least one CF chromosome (table): 21 of them are very rare as they were found on only one CF chromosome in our population. Login to comment

[hide] The spectrum of cystic fibrosis mutations. Trends Genet. 1992 Nov;8(11):392-8. Tsui LC
The spectrum of cystic fibrosis mutations.
Trends Genet. 1992 Nov;8(11):392-8., [PMID:1279852]

Abstract [show]
Although the major mutation causing cystic fibrosis accounts for almost 70% of mutant chromosomes screened, almost 300 sequence alterations have been identified in the gene during the past two and a half years. At least 230 of these mutations are probably associated with disease. This rapid accumulation of data is in part due to the highly coordinated effort by members of the Cystic Fibrosis Genetic Analysis Consortium. The information is not only essential to genetic diagnosis, but also will aid in understanding the structure and function of the protein, and possibly in correlating genotype with phenotype.

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123 8 NO. 11 m []~EVIEWS G551D R553Q G551S I L558S aI~7 S5491 I I 1&559T A455F E5040 I&F508 V520F SS49NII IIR560T PS74H I G458V G480C $492F /" • ss,9 II III* oa. / III / NBF1 ~t ~t NBF2 I I I I I III I I I 11234V G1244E IS1255P D1270N II I Q1291H N1303K G1349D S1251N W1282R] F1286S N1303H Q1283M, FIG[] Cystic fibrosis (missense) mutations located within the two presumptive ATP-binding domains (NBF1 and NBF2) of CFTR. Login to comment

[hide] Genetic determination of exocrine pancreatic funct... Am J Hum Genet. 1992 Jun;50(6):1178-84. Kristidis P, Bozon D, Corey M, Markiewicz D, Rommens J, Tsui LC, Durie P
Genetic determination of exocrine pancreatic function in cystic fibrosis.
Am J Hum Genet. 1992 Jun;50(6):1178-84., [PMID:1376016]

Abstract [show]
We showed elsewhere that the pancreatic function status of cystic fibrosis (CF) patients could be correlated to mutations in the CF transmembrane conductance regulator (CFTR) gene. Although the majority of CF mutations--including the most common, delta F508--strongly correlated with pancreatic insufficiency (PI), approximately 10% of the mutant alleles may confer pancreatic sufficiency (PS). To extend this observation, genomic DNA of 538 CF patients with well-documented pancreatic function status were analyzed for a series of known mutations in their CFTR genes. Only 20 of the 25 mutations tested were found in this population. They accounted for 84% of the CF chromosomes, with delta F508 being the most frequent (71%), and the other mutations accounted for less than 5% each. A total of 30 different, complete genotypes could be determined in 394 (73%) of the patients. The data showed that each genotype was associated only with PI or only with PS, but not with both. This result is thus consistent with the hypothesis that PI and PS in CF are predisposed by the genotype at the CFTR locus; the PS phenotype occurs in patients who have one or two mild CFTR mutations, such as R117H, R334W, R347P, A455E, and P574H, whereas the PI phenotype occurs in patients with two severe alleles, such as delta F508, delta I507, Q493X, G542X, R553X, W1282X, 621 + 1G----T, 1717-1G----A, 556delA, 3659delC, I148T, G480C, V520F, G551D, and R560T.

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10 This result is thus consistent with the hypothesis that PI and PS in CF are predisposed by the genotype at the CFTR locus; the PS phenotype occurs in patients who have one or two mild CFTR mutations, such as R117H, R334W, R347P, A455E, and P574H, whereas the PI phenotype occurs in patients with two severe alleles, such as AF508, A1507, Q493X, G542X, R553X, W1282X, 621 + 1G-PT, 1717-1G--'A, 556delA, 3659delC, I148T, G480C, V520F, G551D, and R560T. Login to comment
57 Intron 4: 621 + 1G-T Exon 7: R334W ......... R347P ........... Exon 9: A455E .......... G458V .......... G480C .......... Exon 10: Q493X .......... A1507 ........... AF508 .......... VS2OF .......... Login to comment
58 Intron 10: 1717-1G-'A Exon 11: G542X .......... S549R ........... G551D .......... R553X .......... R560T .......... Exon 12: Y563N .......... P574H .......... Exon 19: 3659delC ....... Exon 20: W1282X ....... Exon 21: N1303K ..... G460-C A deletion G482-'A A deletion T575-C 621 + 1G-T C1132-T C1172- G C1496-A G1505-'T G1570-T C1609-T 3-bp deletion 3-bp deletion G1690-T G1717-1-A G1756-T T1779-G G1784- A C1789-T G1811-C T1819- A C1853- A C deletion G3978-A C4041-G Asp 110-His Frameshift Arg 117-His Frameshift Ile 148-Thr Splice mutation Arg 334-Trp Arg 347-Pro Ala 455- Glu Gly 458-'Val Gly480-Cys Gln 493- stop del of Ile 507 del of Phe 508 Val 520-Phe Splice mutation Gly 542- stop Ser 549-'Arg Gly 551-WAsp Arg 553- stop Arg 560- Thr Tyr 563- Asn Pro 574-His Frameshift Trp 1282-stop Asn 1303-Lys Dean et al. 1990 White et al. 1991 Dean et al. 1990 Zielenski et al. 1991a F. Rininsland, D. Bozon, and L.-C. Tsui, unpublished data Zielenski et al. 1991a Gasparini et al. 1991 Dean et al. 1990 Kerem et al. 1990b Cuppens et al. 1990 Strong et al. 1991 Kerem et al. 1990b Kerem et al. 1990b Kerem et al. 1989b Jones et al. 1991 Kerem et al. 1990b Kerem et al. 1990b Kerem et al. 1990b Cutting et al. 1990 Cutting et al. 1990 Kerem et al. 1990b Kerem et al. 1990b Kerem et al. 1990b Kerem et al. 1990b Vidaud et al. 1990 Osborne et al. 1990 PI or PS, but not with both. Login to comment
81 Table 4 Classification of CF Gene Mutations as Severe or Mild with Respect to Pancreatic Function Type of Mutation Severe (location) Mild (location) Missense (point mutation) ...... 1148T (exon 4) R117H (exon 4) G480C (exon 9) R334W (exon 7) VS2OF (exon 10) GSS1D (exon 11) R347P (exon 7) RS60T (exon 11) A455E (exon 9) N1303K (exon 21) P574H (exon 12) Single amino acid deletion ........ AFS08 (exon 10) A1507 (exon 10) Stop codon (nonsense) ..... Q493X (exon 10) G542X (exon 11) R553X (exon 11) W1282X (exon 20) Splice junction ... 621 + 1G-T (intron 4) 1717-1G-T (intron 10) Frameshift ........ 556delA (exon 4) 3659delC (exon 19) with any of the mild mutations was associated with PS. Login to comment
85 Accordingly, the mutations R117H, R334W, R347P, A455E, and P574H may be regarded as mild, whereas AF508, AI507, Q493X, G542X, R553X, W1282X, 621 + 1G-T, 1717-1G--A, 556delA, 3659delC, 1148T, G480C, V520F, GSS1D, and R560T are severe. Login to comment

[hide] Assessing the Disease-Liability of Mutations in CF... Cold Spring Harb Perspect Med. 2012 Dec 1;2(12):a009480. doi: 10.1101/cshperspect.a009480. Ferec C, Cutting GR
Assessing the Disease-Liability of Mutations in CFTR.
Cold Spring Harb Perspect Med. 2012 Dec 1;2(12):a009480. doi: 10.1101/cshperspect.a009480., [PMID:23209179]

Abstract [show]
Over 1900 mutations have been reported in the cystic fibrosis transmembrane conductance regulator (CFTR), the gene defective in patients with cystic fibrosis. These mutations have been discovered primarily in individuals who have features consistent with the diagnosis of CF. In some cases, it has been recognized that the mutations are not causative of cystic fibrosis but are responsible for disorders with features similar to CF, and these conditions have been termed CFTR-related disorders or CFTR-RD. There are also mutations in CFTR that do not contribute to any known disease state. Distinguishing CFTR mutations according to their penetrance for an abnormal phenotype is important for clinical management, structure/function analysis of CFTR, and understanding the molecular and cellular mechanisms underlying CF.

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72 Mutations elsewhere in the gene that caused loss of stability include missense mutations such as G480C (p.Gly480Cys) and others that affect domain-domain interactions in CFTR such as R1070Q (p.Arg1070Gln) (Smit et al. 1995; Serohijos et al. 2008). Login to comment

[hide] The cystic fibrosis of exocrine pancreas. Cold Spring Harb Perspect Med. 2013 May 1;3(5):a009746. doi: 10.1101/cshperspect.a009746. Wilschanski M, Novak I
The cystic fibrosis of exocrine pancreas.
Cold Spring Harb Perspect Med. 2013 May 1;3(5):a009746. doi: 10.1101/cshperspect.a009746., [PMID:23637307]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) protein is highly expressed in the pancreatic duct epithelia and permits anions and water to enter the ductal lumen. This results in an increased volume of alkaline fluid allowing the highly concentrated proteins secreted by the acinar cells to remain in a soluble state. This work will expound on the pathophysiology and pathology caused by the malfunctioning CFTR protein with special reference to ion transport and acid-base abnormalities both in humans and animal models. We will also discuss the relationship between cystic fibrosis (CF) and pancreatitis, and outline present and potential therapeutic approaches in CF treatment relevant to the pancreas.

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236 G551D and G480C mutants would be of interest for pancreas, as these mutations are associated with PI. Login to comment

[hide] Cystic fibrosis carrier screening in a North Ameri... Genet Med. 2014 Jul;16(7):539-46. doi: 10.1038/gim.2013.188. Epub 2013 Dec 19. Zvereff VV, Faruki H, Edwards M, Friedman KJ
Cystic fibrosis carrier screening in a North American population.
Genet Med. 2014 Jul;16(7):539-46. doi: 10.1038/gim.2013.188. Epub 2013 Dec 19., [PMID:24357848]

Abstract [show]
PURPOSE: The aim of this study was to compare the mutation frequency distribution for a 32-mutation panel and a 69-mutation panel used for cystic fibrosis carrier screening. Further aims of the study were to examine the race-specific detection rates provided by both panels and to assess the performance of extended panels in large-scale, population-based cystic fibrosis carrier screening. Although genetic screening for the most common CFTR mutations allows detection of nearly 90% of cystic fibrosis carriers, the large number of other mutations, and their distribution within different ethnic groups, limits the utility of general population screening. METHODS: Patients referred for cystic fibrosis screening from January 2005 through December 2010 were tested using either a 32-mutation panel (n = 1,601,308 individuals) or a 69-mutation panel (n = 109,830). RESULTS: The carrier frequencies observed for the 69-mutation panel study population (1/36) and Caucasian (1/27) and African-American individuals (1/79) agree well with published cystic fibrosis carrier frequencies; however, a higher carrier frequency was observed for Hispanic-American individuals (1/48) using the 69-mutation panel as compared with the 32-mutation panel (1/69). The 69-mutation panel detected ~20% more mutations than the 32-mutation panel for both African-American and Hispanic-American individuals. CONCLUSION: Expanded panels using race-specific variants can improve cystic fibrosis carrier detection rates within specific populations. However, it is important that the pathogenicity and the relative frequency of these variants are confirmed.

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34 The 69-mutation panel was a combined panel that included variants approved by the Food and Drug Administration with 10 additional variants (R117C, R352Q, S364P, 3120G>A, 2869insG, G480C, 405+3A>C, 1812-1G>A, 444delA, and F311del) added on the basis of their published frequencies and relevancy to CF. Login to comment
63 This threshold could not be reached Table 1ߒ CFTR allele frequency identified by the CF32 mutation panel Varianta Number of detected alleles Mutation (%) Legacy nomenclature HGVS nomenclature F508delb p.F508del 31,142 68.69 R117Hb p.R117H 5,198 11.46 G542Xb p.G542X 1,162 2.56 G551Db p.G551D 989 2.18 W1282Xb p.W1282X 824 1.82 3120ߙ+ߙ1G>Ab c.2988ߙ+ߙ1G>A 706 1.56 N1303Kb p.N1303K 648 1.43 R553Xb p.R553X 487 1.07 3849ߙ+ߙ10kbC>Tb c.3717ߙ+ߙ12191C>T 436 0.96 621ߙ+ߙ1G>Tb c.489ߙ+ߙ1G>T 410 0.90 1717-1G>Ab c.1585-1G>A 388 0.86 2789ߙ+ߙ5G>Ab c.2657ߙ+ߙ5G>A 382 0.84 I507delb p.I507del 258 0.57 R334Wb p.R334W 257 0.57 R1162Xb p.R1162X 211 0.47 G85Eb p.G85E 199 0.44 1898ߙ+ߙ1G>Ab c.1766ߙ+ߙ1G>A 170 0.37 R347Hc p.R347H 160 0.35 3659delCb c.3528delC 155 0.34 3876delAc c.3744delA 153 0.34 R560Tb p.R560T 132 0.29 S549Nc p.S549N 125 0.28 3905insTc c.3773dupT 121 0.27 R347Pb p.R347P 117 0.26 2184delAb c.2052delA 107 0.24 A455Eb p.A455E 106 0.23 711ߙ+ߙ1G>Tb c.579ߙ+ߙ1G>T 65 0.14 394delTTc c.262_263delTT 56 0.12 V520Fc p.V520F 54 0.12 1078delTc c.948delT 52 0.11 2183AA>Ga,c c.2051_2052delAAinsG 37 0.08 S549Rc p.S549R 31 0.07 Total 45,338 100 a 2183AA>G variant was added to the panel in 2010. b Variants from ACMG/ACOG CF screening panel. c Classified as a CF-causing mutation by the CFTR2 Database. ACMG, American College of Medical Genetics and Genomics; ACOG, American College of Obstetricians and Gynecologists; CF, cystic fibrosis; HGVS, Human Genome Variation Society. Table 2ߒ Continued on next page Table 2ߒ CFTR allele frequency identified by the CF69 mutation panel Varianta Allele frequency Mutation (%) Legacy nomenclature HGVS nomenclature F508delb p.F508del 1,868 60.49 R117Hb p.R117H 274 8.87 D1152Hc p.D1152H 125 4.05 G542Xb p.G542X 98 3.17 L206Wd p.L206W 73 2.36 3120ߙ+ߙ1G>Ab c.2988ߙ+ߙ1G>A 65 2.10 G551Db p.G551D 47 1.52 N1303Kb p.N1303K 42 1.36 W1282Xb p.W1282X 38 1.23 3849ߙ+ߙ10kbC>Tb c.3717ߙ+ߙ12191C>T 28 0.91 3876delAd c.3744delA 28 0.91 F311dele p.F312del 24 0.78 I507delb p.I507del 24 0.78 R553Xb p.R553X 24 0.78 R117Cd p.R117C 22 0.71 621ߙ+ߙ1G>Tb c.489ߙ+ߙ1G>T 21 0.68 1717-1G>Ab c.1585-1G>A 18 0.58 S549Nd p.S549N 18 0.58 R334Wb p.R334W 17 0.55 2789ߙ+ߙ5G>Ab c.2657ߙ+ߙ5G>A 16 0.52 G85Eb p.G85E 14 0.45 3199del6e c.3067_3072delATAGTG 12 0.39 R1066Cd p.R1066C 11 0.36 1898ߙ+ߙ1G>Ab c.1766ߙ+ߙ1G>A 10 0.32 R347Hd p.R347H 10 0.32 R1162 Xb p.R1162X 9 0.29 W1089Xd p.W1089X 9 0.29 2184delAb c.2052delA 8 0.26 2307insAd c.2175dupA 8 0.26 1078delTd c.948delT 7 0.23 R75Xd p.R75X 7 0.23 3120G>Ad c.2988 G>A 6 0.19 3659delCb c.3528delC 6 0.19 Q493Xd p.Q493X 6 0.19 R1158Xd p.R1158X 6 0.19 R560Tb p.R560T 6 0.19 1812-1G>Ad c.1680-1G>A 5 0.16 2055del9>Ad c.1923_1931del9insA 5 0.16 406-1G>Ad c.274-1G>A 5 0.16 A559Td p.A559T 5 0.16 R347Pb p.R347P 5 0.16 S1255Xd p.S1255X 5 0.16 1677delTAd c.1545_1546delTA 4 0.13 711ߙ+ߙ1G>Tb c.579ߙ+ߙ1G>T 4 0.13 E60Xd p.E60X 4 0.13 R352Qd p.R352Q 4 0.13 Y1092Xd p.Y1092X 4 0.13 2183AA>Gd c.2051_2052delAAinsG 3 0.10 3791delCd c.3659delC 3 0.10 3905insTd c.3773dupT 3 0.10 by 10 variants: the 2143delT, A455E, S549R, Y122X, and M1101K mutations, typically observed in Caucasians; 935delA, 2869insG, and Q890X in Hispanics; and 405+3A>C and G480C in the African-American population. Login to comment
79 Six of these variants were specific to African Americans (R75X, G480C, A559T, 2307insA, 3791delC, and S1255X). Login to comment
80 The Table 3ߒ Frequency of 5T/7T/9T genotypes as a result of R117H reflex testing Poly-T alleles Number of detected alleles (%) CF32 panel CF69 panel 5T/5T 23 (0.44) 2 (0.73) 5T/7T 430 (8.27) 26 (9.49) 5T/9T 38 (0.73) 1 (0.37) 7T/7T 4,103 (78.93) 219 (79.92) 7T/9T 604 (11.61) 26 (9.49) 9T/9T 1 (0.02) 0 Total 5,198 (100) 274 (100) 394delTTd c.262_263delTT 3 0.10 G178Rd p.G178R 3 0.10 V520Fd p.V520F 3 0.10 2143delTd c.2012delT 2 0.06 935delAe c.803delA 2 0.06 A455Eb p.A455E 2 0.06 Q890Xd p.Q890X 2 0.06 S549Rd p.S549R 2 0.06 2869insGd c.2737insG 1 0.03 405ߙ+ߙ3A>Ce c.273ߙ+ߙ3A>C 1 0.03 G480Ce p.G480C 1 0.03 M1101Kd p.M1101K 1 0.03 Y122Xd p.Y122X 1 0.03 Total 3,088 100 a 1898ߙ+ߙ5G>Te , 444delA, G330X, S364Pe , K710X, and S1196X mutations were not detected in the target population. Login to comment
115 The extended panel detected 21.7% more mutations (P < 0.01) using six additional race-specific (R75X, G480C, A559T, 2307insA, S1255X, and 3791delC) and seven panethnic variants (see Supplementary Table S2 online). Login to comment

[hide] Impact of heterozygote CFTR mutations in COPD pati... Respir Res. 2014 Feb 11;15:18. doi: 10.1186/1465-9921-15-18. Raju SV, Tate JH, Peacock SK, Fang P, Oster RA, Dransfield MT, Rowe SM
Impact of heterozygote CFTR mutations in COPD patients with chronic bronchitis.
Respir Res. 2014 Feb 11;15:18. doi: 10.1186/1465-9921-15-18., [PMID:24517344]

Abstract [show]
BACKGROUND: Cigarette smoking causes Chronic Obstructive Pulmonary Disease (COPD), the 3rd leading cause of death in the U.S. CFTR ion transport dysfunction has been implicated in COPD pathogenesis, and is associated with chronic bronchitis. However, susceptibility to smoke induced lung injury is variable and the underlying genetic contributors remain unclear. We hypothesized that presence of CFTR mutation heterozygosity may alter susceptibility to cigarette smoke induced CFTR dysfunction. Consequently, COPD patients with chronic bronchitis may have a higher rate of CFTR mutations compared to the general population. METHODS: Primary human bronchial epithelial cells derived from F508del CFTR heterozygotes and mice with (CFTR+/-) and without (CFTR+/+) CFTR heterozygosity were exposed to whole cigarette smoke (WCS); CFTR-dependent ion transport was assessed by Ussing chamber electrophysiology and nasal potential difference measurements, respectively. Caucasians with COPD and chronic bronchitis, age 40 to 80 with FEV1/FVC < 0.70 and FEV1 < 60% predicted, were selected for genetic analysis from participants in the NIH COPD Clinical Research Network's Azithromycin for Prevention of Exacerbations of COPD in comparison to 32,900 Caucasian women who underwent prenatal genetic testing. Genetic analysis involved an allele-specific genotyping of 89 CFTR mutations. RESULTS: Exposure to WCS caused a pronounced reduction in CFTR activity in both CFTR (+/+) cells and F508del CFTR (+/-) cells; however, neither the degree of decrement (44.7% wild-type vs. 53.5% F508del heterozygous, P = NS) nor the residual CFTR activity were altered by CFTR heterozygosity. Similarly, WCS caused a marked reduction in CFTR activity measured by NPD in both wild type and CFTR heterozygous mice, but the severity of decrement (91.1% wild type vs. 47.7% CF heterozygous, P = NS) and the residual activity were not significantly affected by CFTR genetic status. Five of 127 (3.9%) COPD patients with chronic bronchitis were heterozygous for CFTR mutations which was not significantly different from controls (4.5%) (P = NS). CONCLUSIONS: The magnitude of WCS induced reductions in CFTR activity was not affected by the presence of CFTR mutation heterozygosity. CFTR mutations do not increase the risk of COPD with chronic bronchitis. CFTR dysfunction due to smoking is primarily an acquired phenomenon and is not affected by the presence of congenital CFTR mutations.

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81 As expected based on genotype-phenotype correlations in the disease [33], HBE cells derived from a F508del CFTR heterozygote had slightly lower CFTR activity at baseline than wild type monolayers as measured by Table 1 List of CFTR mutations analyzed F508del R117H 1717-1G > A R117C G85E R334W 1898 + 1G > A Y122X A455E R347P 2184delA G178R I507del R553X 2789 + 5G > A G314E G542X R560T 3120 + 1G > A G330X G551D W1282X 3659delC R347H N1303K 621 + 1G > T K710X 406-1G > A R1162X 711 + 1G > T E60X G480C R1066C W1089X V520F A559T S1196X Q1238X S1251N S1255X 663delT 935delA 1161delC 1288insTA 2184insA 2307insA 2711delT 2869insG R709X R764X R1158X 574delA Q493X 1898 + 5G > T 3905insT I506T 3849 + 10kbC > T 712-1G > T Q98R Q552X S549N 1078delT H199Y 444delA S549R (T > G) 2143delT P205S 2043delG 1811 + 1.6kbA > G 3272-26A > G L206W 3791delC Y1092X (C > G) 3199del6 F508C 2108delA Y1092X (C > A) D1152H V520I 3667del4 394delTT 3876delA M1101K 1677delTA W1098X (TGA) 1812-1G > A 4016insT 1609delCA 3171delC response to forskolin stimulation (49.3 &#b1; 11.5 bc;A/cm2 in CFTR (+/+) vs. 40.5 &#b1; 5.3 bc;A/cm2 in CFTR (+/-), although this was not statistically significant (Figure 1A,B). Login to comment

[hide] Cystic fibrosis: toward personalized therapies. Int J Biochem Cell Biol. 2014 Jul;52:192-200. doi: 10.1016/j.biocel.2014.02.008. Epub 2014 Feb 20. Ikpa PT, Bijvelds MJ, de Jonge HR
Cystic fibrosis: toward personalized therapies.
Int J Biochem Cell Biol. 2014 Jul;52:192-200. doi: 10.1016/j.biocel.2014.02.008. Epub 2014 Feb 20., [PMID:24561283]

Abstract [show]
Cystic fibrosis (CF), the most common, life-threatening monogenetic disease in Caucasians, is caused by mutations in the CFTR gene, encoding a cAMP- and cGMP-regulated epithelial chloride channel. Symptomatic therapies treating end-organ manifestations have increased the life expectancy of CF patients toward a mean of 40 years. The recent development of CFTR-targeted drugs that emerged from high-throughput screening and are capable of correcting the basic defect promises to transform the therapeutic landscape from a trial-and-error prescription to personalized medicine. This stratified approach is tailored to a specific functional class of mutations in CFTR, but can be refined further to an individual level by exploiting recent advances in ex vivo drug testing methods. These tests range from CFTR functional measurements in rectal biopsies donated by a CF patient to the use of patient-derived intestinal or pulmonary organoids. Such organoids may serve as an inexhaustible source of epithelial cells that can be stored in biobanks and allow medium- to high-throughput screening of CFTR activators, correctors and potentiators on the basis of a simple microscopic assay monitoring organoid swelling. Thus the recent breakthrough in stem cell biology allowing the culturing of mini-organs from individual patients is not only relevant for future stem cell therapy, but may also allow the preclinical testing of new drugs or combinations that are optimally suited for an individual patient.

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1620 Most CFTR trafficking mutants, including F508del, with a few exceptions (e.g. G480C; N287Y), show additional defects in channel gating function, and most PCs and PRs identified thus far only partially normalize the channel conformational defect. Login to comment