ABCMdb

ABCC7 p.Gly27*

ClinVar:

c.80G>A , p.Gly27Glu ? , not provided
c.79G>C , p.Gly27Arg ? , not provided
c.79G>T , p.Gly27* ? , not provided
c.79G>A , p.Gly27Arg ? , not provided

CF databases:

c.80G>A , p.Gly27Glu (CFTR1) D , This mutation, in exon 2, was found in a French male patient and was detected by DGGE using chemical clamps and identified by direct sequencing : G27E (G->A at 212). This mutation has been found in one among 50 non-[delta]F508 CF chromosomes. The patient is sufficient pancreatic, presents a mild pulmonary form and male infertility. He has the [delta]F508 mutation on the other chromosome.
c.79G>T , p.Gly27* D , CF-causing
c.79G>A , p.Gly27Arg (CFTR1) D , This mutation, in exon 2, was detected by SSCA analysis. The G27R (G>A at 211) mutation was found in one argentinean patient. The male patient died at 14 years old, diagnosed at 2 months of age, who carries the F508del mutation on the other chromosome.
c.79G>C , p.Gly27Arg (CFTR1) ? , This mutation was identified on one Czech CF chromosome

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Publications
[hide] Evaluation of gene targeting by homologous recombi... Mol Reprod Dev. 2003 Oct;66(2):115-25. Williams SH, Sahota V, Palmai-Pallag T, Tebbutt SJ, Walker J, Harris A
Evaluation of gene targeting by homologous recombination in ovine somatic cells.
Mol Reprod Dev. 2003 Oct;66(2):115-25., [PMID:12950098]

Abstract [show]
Mouse models for some human genetic diseases are limited in their applications since they do not accurately reproduce the phenotype of the human disease. It has been suggested that larger animals, for example sheep, might produce more useful models, as some aspects of sheep physiology and anatomy are more similar to those of humans. The development of methods to clone animals from somatic cells provides a potential novel route to generate such large animal models following gene targeting. Here, we assess targeting of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in ovine somatic cells using homologous recombination (HR) of targeting constructs with extensive (>11 kb) homology. Electroporation of these constructs into ovine fetal and post-natal fibroblasts generated G418-resistant clones, but none analyzed had undergone HR, suggesting that at least for this locus, it is an extremely inefficient process. Karyotyping of targeted ovine fetal fibroblasts showed them to be less chromosomally stable than post-natal fibroblasts, and, moreover, extended culture periods caused them to senesce, adversely affecting their viability for use as nuclear transfer donor cells. These data stress the importance of donor cell choice in somatic cell cloning and suggest that culture time be kept to a minimum prior to nuclear transfer in order to maximize cell viability.

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Sentences [show]
No. Sentence Comment
40 The G27X mutation in exon 2, which has been reported in a CF patient (Shackleton and Harris, 1992), is caused by a G > T base change introducing a premature stop codon at amino acid 27 in the CFTR protein. Login to comment
41 Primers VIN9 (50 -AAGAAATGATACAGACA- GCGCTTGGAATTCGTCAG-30 ) and VIN10 (50 -TC- TGACGAATTCCAAGCGCTGTCTGTATCATTTCT-30 ) were designed to contain the G27X stop codon mutation (shown in bold) and a single base was inserted downstream of the G27X mutation to create a frame shift mutation and generate an Eco RI restriction enzyme site (shown in italics). Login to comment
42 The G27X mutation was introduced into the 4.5 kb exon 2-containing clone by the QuickChange Site-directed Mutagenesis Kit (Stratagene, La Jolla, CA). Login to comment
133 Long range PCR was also applied to the analysis of the G27X-targeted cells using the primer pair GLONGF/ GLONGR that amplified the intron 1/exon 2 region of ovine CFTR including 6.39 kb from the G27XDTneo targeting construct (Fig. 1). Login to comment

[hide] Mutational spectrum of cystic fibrosis patients fr... Mol Genet Metab. 2006 Apr;87(4):370-5. Epub 2006 Jan 19. Ramirez AM, Ramos MD, Jimenez J, Ghio A, de Botelli MM, Rezzonico CA, Marques I, Pereyro S, Casals T, de Kremer RD
Mutational spectrum of cystic fibrosis patients from Cordoba province and its zone of influence: implications of molecular diagnosis in Argentina.
Mol Genet Metab. 2006 Apr;87(4):370-5. Epub 2006 Jan 19., [PMID:16423550]

Abstract [show]
Cystic Fibrosis (CF) is an autosomal recessive disorder affecting 1/2000-4000 newborns in Caucasian populations. This lethal disease mainly affects respiratory and digestive organs as well as fertility in man. So far, the CF prevalence and mutational spectrum have showed specificity among populations and regions, making it necessary to establish them in each one. In this study, we present the spectrum and frequency of CFTR gene mutations in CF patients from Cordoba (a province with 3.1 millions inhabitants in the middle of Argentina) and its zone of influence, to offer an accurate genetic testing. The study includes 78 families in which 98 patients fulfilled clinical criteria to CF diagnosis. The strategy for the molecular diagnosis comprised analysis of 21 common mutations, microsatellite haplotypes and the complete CFTR gene analysis using scanning techniques followed by sequencing of the abnormal migration patterns. Our first step led us to the identification of 10 mutations that represented 76% of alleles. Another four mutations (p.R1066C, c.1811 + 1.6 kbA > G, c.711 + 1G > T, and p.G85E) were found based on the microsatellite haplotype-mutation association. Finally, 14 mutations were characterized after the CFTR gene scanning, three of them are not previously described (p.G27R, c.622-2A > G, and p.W277R). In summary, we have identified 27 mutations accounting for 94.23% of CF alleles. This characteristic mutational spectrum highlights the 14 most frequent mutations (>1%) in the Cordoba region.

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No. Sentence Comment
98 About of the novel mutations, our results suggest that p.G27R correlate with a severe phenotype likewise that p.G27X previously described, while another mutation in the same codon, p.G27E, has a milder clinical presentation of CF with late onset of symptoms, diagnosed at 41 years with CBAVD, pancreatic suYciency and mild pulmonary disease [20,21]. Login to comment

[hide] Mutation characterization of CFTR gene in 206 Nort... Hum Mutat. 1996;8(4):340-7. Hughes DJ, Hill AJ, Macek M Jr, Redmond AO, Nevin NC, Graham CA
Mutation characterization of CFTR gene in 206 Northern Irish CF families: thirty mutations, including two novel, account for approximately 94% of CF chromosomes.
Hum Mutat. 1996;8(4):340-7., [PMID:8956039]

Abstract [show]
A variety of mutation detection techniques, including restriction endonuclease digestion, allele specific oligonucleotides, and automated fluorescent sequencing, were used in the identification of 15 CFTR mutations representing 86.7% of CF chromosomes in 206 Northern Irish cystic fibrosis (CF) families. A systematic analysis of the 27 exons and intron/exon boundaries of the CFTR gene was performed using denaturing gradient gel electrophoresis (DGGE) in an attempt to characterise the 55 unknown CF mutations in 51 patients. Twenty different mutations were detected by DGGE on 30 chromosomes accounting for a further 7.3% of CF alleles. Fifteen of these mutations had not previously been found in Northern Ireland, and two are novel, M1I(G > T) and V562L. In total, 30 CFTR mutations account for 93.9% of the 412 Northern Irish CF chromosomes tested. The three major CF mutations in Northern Ireland are delta F508, G551D, and R117H with respective frequencies of 68.0%, 5.1%, and 4.1%. The efficacy of the DGGE technique was proven by the detection of 77 out of 77 control variants from all the CFTR exons. DGGE is a highly efficient and sensitive method for mutation screening especially in large genes where the mutation spectrum is known to be heterogeneous.

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No. Sentence Comment
71 All Mutationsand Polvmorphisms(control and new) Identified by DGGE in This Studv 1 2 3 4 5 6a 6b 7 8 9 10 11 12 13partl 13part2 13part3 13part4 14a 14b 15 16 17a 17bpartl 17bpart2 18 19 20 21 22 23 24 _ _ _ _ _ ~ ~ ~ DGGE Denaturant Run time (exon) Mutation" (range of %) Voltage (hr) 125G>C (p),129G>C (p),M11 (G>T), Q2X, 182delT 40-80 150 4 G27X. Login to comment

[hide] Analysis of mutations and alternative splicing pat... Hum Mol Genet. 1994 Jul;3(7):1141-6. Hull J, Shackleton S, Harris A
Analysis of mutations and alternative splicing patterns in the CFTR gene using mRNA derived from nasal epithelial cells.
Hum Mol Genet. 1994 Jul;3(7):1141-6., [PMID:7526925]

Abstract [show]
Ten to fifteen percent of CF chromosomes carry mutations which are not detected by routine screening of the CFTR gene for known mutations. Many techniques have been used to screen the CFTR gene for these remaining mutations. Most of the methods use genomic DNA, and since the CFTR gene contains 27 exons, are necessarily labour intensive. We have screened the entire coding region of CFTR, by chemical cleavage of 7 overlapping segments of amplified cDNA. Using this method we have identified 4 sequence changes which had not been detected by screening genomic DNA, and successfully detected 10 out of 13 known mutations. In addition, we have identified 8 alternatively spliced forms of CFTR mRNA, 4 of which have not been described previously. These include transcripts lacking a) exon 3, b) exons 2 + 3, c) exons 9 + 12, and d) the final 357 bp of exon 15 as a result of use of the cryptic splice donor site CA2863/GTTCGT).

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Sentences [show]
No. Sentence Comment
47 The 4 mutations that were not detected were 182delT (11), G27X (15), R553X (14) and W1O98R (Tsui pers comm). Login to comment
51 182delT (11) G27X (15) G85E0 (8) £92*? Login to comment
75 Mutations not detected by the chemical cleavage technique The mutations that this method failed to detect were 182delT (exon 1, A-6 set), G27X (G to T substitution, exon 2, A-6 set), R553X (C to T substitution, exon 11, B set), and W1098R (T to C substitution, exon 17b, E set). Login to comment
82 Analysis of the full length cDNA fragments A-6 and E respectively, by direct sequencing in the case of G27X, and by restriction enzyme digestion for the W1098R mutation (the T to C mutation creates a unique Mspl recognition site in the E fragment), demonstrated that both mutations were present in their respective full length fragments of amplified cDNA. Login to comment
100 The G27X mutation results from a G to T change, producing a C-T mismatch which should be readily detectable by hydroxylamine. Login to comment

[hide] Sensitivity of single-strand conformation polymorp... Hum Mol Genet. 1994 May;3(5):801-7. Ravnik-Glavac M, Glavac D, Dean M
Sensitivity of single-strand conformation polymorphism and heteroduplex method for mutation detection in the cystic fibrosis gene.
Hum Mol Genet. 1994 May;3(5):801-7., [PMID:7521710]

Abstract [show]
The gene responsible for cystic fibrosis (CF) contains 27 coding exons and more than 300 independent mutations have been identified. An efficient and optimized strategy is required to identify additional mutations and/or to screen patient samples for the presence of known mutations. We have tested several different conditions for performing single-stranded conformation polymorphism (SSCP) analysis in order to determine the efficiency of the method and to identify the optimum conditions for mutation detection. Each exon and corresponding exon boundaries were amplified. A panel of 134 known CF mutations were used to test the efficiency of detection of mutations. The SSCP conditions were varied by altering the percentage and cross-linking of the acrylamide, employing MDE (an acrylamide substitute), and by adding sucrose and glycerol. The presence of heteroduplexes could be detected on most gels and in some cases contributed to the ability to distinguish certain mutations. Each analysis condition detected 75-98% of the mutations, and all of the mutations could be detected by at least one condition. Therefore, an optimized SSCP analysis can be used to efficiently screen for mutations in a large gene.

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Sentences [show]
No. Sentence Comment
120 Exon 1: S4X (24), 186-13C-G (F£rec et al., pers. comm.); Exon 2: G27X (Shacldeton and Harris, pers. comm.), Q30X (Chilldn aal., pers. comm.), R31L (Zielenski et al., pers. comm.), Q39X (25); Exon 3: 300delA (Malone et al., pers. comm.), W57G (Ferrari et al., pers. comm.), W57X (26), E60X (Malone et al., pers. comm.), R74W (Claustres et al., pers. comm.), R75Q (27), G85E (28), 394delTT (Claustres et al., pers. comm.), L88X (Maceketal., pers. comm.), L88S (Malone et al., pers. comm.), 405 + 1G-A (Dork and Tummler, pers. comm.); Exon 4: E92K (Chillon et al., pers. comm.), E92X (D6rk a al., pers. comm.), P99L (Schwartz and Holmberg, pers. comm.), 441delA (Zielenski et al., pers. comm.), 444delA (29), 457TAT-C- (F£rec et al., pers. comm., (21), Dl 10H (14), Rl 17C (D6rk et al., pers. comm.), Rl 17H (14), A120T (Chillon et al., pers. comm.), 541delC (30), 556delA (28), I148T (Rininsland et al., pers. comm.), Q151X (Shacldeton et al., pers. comm.), 621 + 1C-T (28), 622-2A-C (31); Exon5:G178R (28), 681delC (Zielenski a al., pers. comm.), 711 + 1G-T (28); Exon 6a: H199Y (Dork and Tummler, pers. comm.), H199Q (Dean etal., pers. comm.), L206W (Claustres et al., pers. comm.), Q220X (Shacldeton and Harris, pers. comm., Schwartz and Holmberg, pers. comm.), 852del22 (32); Exon 6b: 977insA (33); Exon7:F311L(34). Login to comment

[hide] G27X: a novel mutation in exon 2 of the CF gene. Hum Mol Genet. 1992 Sep;1(6):445. Shackleton S, Harris A
G27X: a novel mutation in exon 2 of the CF gene.
Hum Mol Genet. 1992 Sep;1(6):445., [PMID:1284531]

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Sentences [show]
No. Sentence Comment
10 The patient with the G27X/AF508 genotype has classical cystic fibrosis and pancreatic insufficiency. Login to comment
15 It remains to be seen whether G27X will be common enough to occur sufficiently often in a homozygote state for any worthwhile genotype/phenotype predictions to be made. Login to comment