ABCMdb

ABCC7 p.Leu441Pro

ClinVar:	c.1322T>C , p.Leu441Pro ? , not provided
CF databases:	c.1322T>C , p.Leu441Pro (CFTR1) ? , Other mutation is D979A (c.2936A>C)
Predicted by SNAP2:	A: D (75%), C: D (63%), D: D (91%), E: D (91%), F: D (75%), G: D (91%), H: D (85%), I: N (53%), K: D (91%), M: D (59%), N: D (85%), P: D (91%), Q: D (80%), R: D (91%), S: D (85%), T: D (80%), V: D (59%), W: D (85%), Y: D (80%),
Predicted by PROVEAN:	A: D, C: D, D: D, E: D, F: D, G: D, H: D, I: N, K: D, M: N, N: D, P: D, Q: D, R: D, S: D, T: D, V: N, W: D, Y: D,

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[hide] A finger sweat chloride test for the detection of ... Pancreas. 2004 Apr;28(3):e80-5. Naruse S, Ishiguro H, Suzuki Y, Fujiki K, Ko SB, Mizuno N, Takemura T, Yamamoto A, Yoshikawa T, Jin C, Suzuki R, Kitagawa M, Tsuda T, Kondo T, Hayakawa T
A finger sweat chloride test for the detection of a high-risk group of chronic pancreatitis.
Pancreas. 2004 Apr;28(3):e80-5., [PMID:15084988]

Abstract [show]
OBJECTIVES: Mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene are associated with chronic pancreatitis in Caucasians. We developed a simple method for measuring finger sweat chloride concentration to test whether CFTR dysfunction underlies chronic pancreatitis in Japan where cystic fibrosis (CF) is rare. METHODS: We studied 25 patients with chronic (21 alcoholic and 4 idiopathic) pancreatitis and 25 healthy volunteers. Sweat chloride concentrations were measured by a finger sweat chloride test. We analyzed DNA for 20 common CFTR mutations in Europeans, 9 CF-causing mutations in Japanese, and 2 polymorphic loci, a poly-T tract and (TG) repeats, at intron 8. RESULTS: Thirteen patients (52%) had sweat chloride levels >60 mmol/L, a level consistent with CF, while only 4 (16%) healthy subjects exceeded this level. The 29 CF mutations and the 5T allele were detected in neither the patients nor controls. The (TG) 12 allele was common in both the patients (58%) and controls (48%). The (TG) 12/12 genotype was common in alcoholic pancreatitis (29%) compared with the (TG) 11/11 (10%). Patients with the (TG) 12/12 genotype had significantly higher sweat chloride concentrations than the controls. CONCLUSION: CFTR dysfunction as evidenced by a finger sweat chloride test is present in about half of Japanese patients with chronic pancreatitis, suggesting that this test may be useful for detecting the high-risk group. A higher proportion of the (TG) 12 allele may be a genetic background for elevated sweat chloride concentrations in Japanese patients.

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No. Sentence Comment
51 The 9 CF-causing mutations (R75X, Q98R, M152R, R347H, L441P, L571S, D979A, H1085R, and T1086I) in Japa- nese20,25-28 were screened by SNP typing with Masscode System (Shimadzu, Kyoto, Japan). Login to comment

[hide] Genetic evidence for CFTR dysfunction in Japanese:... J Med Genet. 2004 May;41(5):e55. Fujiki K, Ishiguro H, Ko SB, Mizuno N, Suzuki Y, Takemura T, Yamamoto A, Yoshikawa T, Kitagawa M, Hayakawa T, Sakai Y, Takayama T, Saito M, Kondo T, Naruse S
Genetic evidence for CFTR dysfunction in Japanese: background for chronic pancreatitis.
J Med Genet. 2004 May;41(5):e55., [PMID:15121783]

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219 The nine CF causing (R75X, Q98R, M152R, R347H, L441P, L571S, D979A, H1085R, and T1086I) and two non-CF causing (Q1352H and R1453W) mutations in Japanese6 22-24 were screened by SNP typing with a Masscode system (Shimadzu, Kyoto, Japan) and confirmed by sequence analysis in positive and equivocal cases. Login to comment

[hide] The L441P mutation of cystic fibrosis transmembran... J Korean Med Sci. 2010 Jan;25(1):166-71. Epub 2009 Dec 26. Gee HY, Kim CK, Kim SW, Lee JH, Kim JH, Kim KH, Lee MG
The L441P mutation of cystic fibrosis transmembrane conductance regulator and its molecular pathogenic mechanisms in a Korean patient with cystic fibrosis.
J Korean Med Sci. 2010 Jan;25(1):166-71. Epub 2009 Dec 26., [PMID:20052366]

Abstract [show]
Cystic fibrosis (CF) is an autosomal recessive disorder usually found in populations of white Caucasian descent. CF is caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. A 5-yr-old Korean girl was admitted complaining of coughing and greenish sputum. Chest radiographs and computed tomographic (CT) scan revealed diffuse bronchiectasis in both lungs. The patient had chronic diarrhea and poor weight gain, and the abdominal pancreaticobiliary CT scan revealed atrophy of the pancreas. Finally, CF was confirmed by the repeated analysis of the quantitative pilocarpine iontophoresis test. The chloride concentration of sweat samples taken from both forearms of the pateint was an average of 88.7 mM/L (normal value <40 mM/L). After a comprehensive search for mutations in the CFTR gene, the patient was found to carry the non-synonymous L441P mutation in one allele. Molecular physiologic analysis of the L441P mutation of CFTR revealed that the L441P mutation completely abolished the CFTR Cl(-) channel activity by disrupting proper protein folding and membrane trafficking of CFTR protein. These results confirmed the pathogenicity of the L441P mutation of CFTR circulating in the Korean population. The possibility of CF should be suspected in patients with chronic bronchiectasis, although the frequency of CF is relatively rare in East Asia.

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8 The genetic analysis of patient`s CFTR gene and the related molecular functional study revealed that the patient had a pathogenic L441P mutation in one allele. Login to comment
14 J Korean Med Sci 2010; 25: 166-71 ISSN 1011-8934 DOI: 10.3346/jkms.2010.25.1.166 The L441P Mutation of Cystic Fibrosis Transmembrane conductance Regulator and its Molecular Pathogenic Mechanisms in a Korean Patient with Cystic Fibrosis Cystic fibrosis (CF) is an autosomal recessive disorder usually found in populations of white Caucasian descent. Login to comment
21 After a comprehensive search for mutations in the CFTR gene, the patient was found to carry the non-synonymous L441P mutation in one allele. Login to comment
22 Molecular physiologic analysis of the L441P mutation of CFTR revealed that the L441P mutation completely abolished the CFTR Cl-channel activity by disrupting proper protein folding and membrane trafficking of CFTR protein. Login to comment
23 These results confirmed the pathogenicity of the L441P mutation of CFTR circulating in the Korean population. Login to comment
46 Interestingly, a non-synonymous L441P mutation of CFTR was identified in one allele by DGGE and consecutive nucleotide sequencings (Fig. 2). Login to comment
49 However, no CFTR mutations including L441P were found in the blood samples from patient`s mother (Fig. 2). Login to comment
50 Therefore, the L441P mutation was assumed to come from patient`s father. Login to comment
51 It has been reported that the L441P mutation of CFTR is associated with CF in Japan and its allele frequency was estimated around 4.5% among CF patients in Japan (5). Login to comment
52 However, the molecular pathogenic mechanisms of the L441P mutation of CFTR are currently unknown. Login to comment
53 Therefore, we investigated the disease-causing mechanism of L441P using Fig. 1. Login to comment
58 A B A B Patient A WT Band C Lysate Blot: anti-CFTR Ab (M3A7) L441P WT Mother Exon 9 (Ex9.2) L441P 250 CTG → CCG: L441PPatient Forward Reverse T/C A/G T A Forward Reverse Mother Fig. 2. Login to comment
62 (B) Nucleotide sequencing shows that the patient`s CFTR gene contains a mutation changed from T nucleotide at 1454 to C (heterozygous for L441P, CTG:Leu → CCG; Pro). Login to comment
63 KDa 160 105 Biotinylation Band B B WT Lysate Blot: anti-calnexin Ab L441P WT L441P 105 KDa 75 Biotinylation Fig. 3. Login to comment
64 Immunoblotting and surface biotinylation of L441P mutant CFTR protein. Login to comment
65 HEK 293 cells were transfected with plasmids for wild type CFTR or CFTR carrying the L441P mutation and protein samples were blotted with anti-CFTR M3A7 antibody (Cell Signaling Technology, Danvers, MA). Login to comment
66 (A) Most of the wild type CFTR protein was detected as the fully glycosylated mature form (band C), whereas virtually all of the L441P mutant protein appeared as the core-glycosylated form of around 150 kDa (band B). Login to comment
71 The CFTR plasmid carrying a L441P mutation was constructed by site-directed mutagenesis using QuickChange kit (Stratagene, La Jolla, CA, USA) with pCMV-CFTR plasmid according to the manufacturer`s protocol. Login to comment
73 The total amount of CFTR protein was compared in HEK 293 cells transfected with plasmids for wild type CFTR or CFTR carrying the L441P mutation by immunoblotting of total cell lysates. Login to comment
76 In immunoblotting of cell lysates, most of the wild type CFTR protein was detected as the fully glycosylated mature form, whereas virtually all of L441P mutant proteins appeared as the ER core-glycosylated form of about 150 kDa, also known as band B (Fig. 3). Login to comment
77 These results imply that the L441P mutant CFTR protein has a defect in the ER-to-Golgi trafficking of the secretory pathway of membrane protein. Login to comment
78 Consequently, the surface biotinylation results revealed that the L441P mutant protein failed to reach the plasma membrane, whereas the fully glycosylated form of wild type CFTR was expressed on the cell surface (Fig. 3). Login to comment
79 To investigate the intracellular localizations of the mutant CFTR, immunostaining was performed in HEK 293 cells transfected with plasmids for wild type CFTR or CFTR carrying the L441P mutation. Login to comment
83 On the other hand, L441P mutant protein was found in the ER, which was confirmed by co-localization with calnexin, an ER membrane protein (Fig. 4). Login to comment
89 However, the cAMP treatment (5 μM FSK) failed to activate the Cl- currents in cells transfected with L441P mutant CFTR (Fig. 5). Login to comment
95 Immunocytochemistry of L441P mutant CFTR. HEK 293 cells were transfected with plasmids for wild type CFTR or CFTR carrying the L441P mutation, immunostained with anti-CFTR 24-1 antibody (R&D Systems) and fluorescein isothiocyante-conjugated secondary antibodies. Login to comment
98 Wild type Calnexin Merge L441P Calnexin Merge ease progression. Login to comment
118 A thorough examination on the coding regions and exon-intron splicing junctions revealed the L441P non-synonymous mutation in one allele. Login to comment
128 Fig. 5. cAMP-activated Cl-channel activity of L441P mutant CFTR. HEK 293 cells were transfected with plasmids for wild type CFTR or CFTR carrying the L441P mutation and the cAMP-activated Cl-channel activity was measured in the whole cell configuration. Login to comment
130 Mean currents were normalized as current densities (pA/pF, n=6 for wild type CFTR and n=10 for L441P mutant CFTR). Login to comment
132 Currentdensity(pA/pF) 45 40 35 30 25 20 15 10 5 0 2,500 2,000 1,500 1,000 500 -500 -1,000 -1,500 -2,000 -2,500 WT L441P 20 40 60 80 100 120 140 P <0.01 Patch clamp I-V curve pA mV A B -140 -120-100 -80 -60 -40 -20 L441P WT Defects in the protein folding and processing during the secretory pathway of membrane protein are the major molecular pathogenic mechanisms of mutant CFTR (4). Login to comment
134 The present study is the first study that substantially demonstrated the pathogenicity of the L441P mutation. Login to comment
135 An integrated molecular physiologic examination revealed that the L441P mutation causes a processing defect. Login to comment
136 The L441P mutant protein was not fully glycosylated, which implies that the L441P mutant protein can not travel to the Golgi-complex and subsequently to the membrane. Login to comment
137 This was verified by the absence of L441P mutant protein in the plasma membrane in immunostatining and surface biotinylation experiments. Login to comment
138 Consequently, the cAMP-activated chloride channel activities of CFTR were completely deteriorated by the L441P mutation. Login to comment

[hide] Heterogeneous spectrum of CFTR gene mutations in K... Korean J Lab Med. 2011 Jul;31(3):219-24. Epub 2011 Jun 28. Jung H, Ki CS, Koh WJ, Ahn KM, Lee SI, Kim JH, Ko JS, Seo JK, Cha SI, Lee ES, Kim JW
Heterogeneous spectrum of CFTR gene mutations in Korean patients with cystic fibrosis.
Korean J Lab Med. 2011 Jul;31(3):219-24. Epub 2011 Jun 28., [PMID:21779199]

Abstract [show]
BACKGROUND: Cystic fibrosis (CF) is one of the most common hereditary disorders among Caucasians. The most common mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene have been well established among Caucasian populations. In Koreans, however, there are very few cases of genetically confirmed CF thus far, and the spectrum of mutations seems quite different from that observed in Caucasians. METHODS: In the present study, we describe the cases of 2 Korean CF patients, present sequencing results identifying mutations in their CFTR gene, and summarize the results of CFTR mutational spectrum from previously reported Korean CF patients. The mutations described were identified by performing direct sequencing analysis of the complete coding regions and flanking intronic sequences of the CFTR gene, followed by multiplex ligation-dependent probe amplification (MLPA) analysis in order to detect gene deletions or duplications that could not be identified by a direct sequencing method. RESULTS: Three CFTR mutations were identified in the 2 patients, including p.Q98R, c.2052delA, and c.579+5G>A. In an analysis of 9 Korean CF patients that included the 2 patients presented in this study, p.Q98R mutation was the only recurrently observed mutation with a frequency of 18.8% (3/16 alleles). Furthermore, only one of the mutations (c.3272-26A>G) was found among the 32 common mutations in the screening panel for Caucasians from the Cystic Fibrosis Mutation Database. CONCLUSIONS: Sequencing of the entire CFTR gene followed by MLPA analysis, rather than using the targeted sequencing-based screening panel for mutations commonly found in Caucasian populations, is recommended for genetic analysis of Korean CF patients.

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No. Sentence Comment
90 del Deletion + - NA NA 7 Q1291X Exon20 4,003 C>T Nonsense Sequencing + - + NA [14] IVS8 T5 Splicing Sequencing - + - NA 8 L88X Exon3 263 T>G Nonsense Sequencing + - NA NA [29] R697KfsX33 Exon13 2,089-2,090 insA Insertion Sequencing - + NA NA 9 L441P Exon9 1,454 T>C Missense Sequencing&DGGE ND - ND NA [19] Abbreviations:IVS,interveningsequence;MLPA,multiplexligation-dependentprobeamplification;ND,notdone;NA,notapplicable;DGGE,denaturinggradientgelelectrophoresis. Login to comment
81 The identified mutations included 3 missense mutations (p.Q98R, p.Q1352H, and p.L441P), 3 nonsense mutations (p.Q220X, p.Q1291X, and p.L88X), 1 duplication with frameshift (c.3908dupA), 1 insertion with frameshift (c.2089-2090insA), 4 splice site mutations (c.1766+2T>C, c.3272-26A>G, c.579+5G>A, and IVS8-T5) and 2 deletion mutations (c.2052delA and c.2623-?_2751+?del). Login to comment

[hide] Erratum: Heterogeneous spectrum of CFTR gene mutat... Ann Lab Med. 2015 Jan;35(1):185-6. doi: 10.3343/alm.2015.35.1.185.
Erratum: Heterogeneous spectrum of CFTR gene mutations in Korean patients with cystic fibrosis.
Ann Lab Med. 2015 Jan;35(1):185-6. doi: 10.3343/alm.2015.35.1.185., [PMID:25553309]

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[This corrects the article on p. 219 in vol. 31.].

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No. Sentence Comment
7 del Deletion + - NA NA 7 Q1291X Exon 20 4,003 C>T Nonsense Sequencing + - + NA [14] IVS8 T5 Splicing Sequencing - + - NA 8 L88X Exon 3 263 T>G Nonsense Sequencing + - NA NA [29] R697KfsX33 Exon 13 2,089-2,090 insA Insertion Sequencing - + NA NA 9 L441P Exon 9 1,454 T>C Missense Sequencing & DGGE ND - ND NA [19] Abbreviations: IVS, intervening sequence; MLPA, multiplex ligation-dependent probe amplification; ND, not done; NA, not applicable; DGGE, denaturing gradient gel electrophoresis. Login to comment
10 del Deletion MLPA + - NA NA 7 Q1291X Exon 20 3,871 C>T Nonsense Sequencing + - + NA [14] IVS8 T5 Splicing Sequencing - + - NA 8 L88X Exon 3 263 T>G Nonsense Sequencing + - NA NA [29] R697KfsX33 Exon 13 2,089 dupA Insertion Sequencing - + NA NA 9 L441P Exon 9 1,322 T>C Missense Sequencing & DGGE ND - ND NA [19] *Nucleotide numbers are based on the CFTR reference mRNA sequence, NM_000492.3. Login to comment