rs113857788

chr7-117664780-G-Cchr7-117664780-G-T

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 2P and 9B. PM1 BP4_Strong BS1_Supporting BS2

The NM_000492.4(CFTR):c.4056G>C(p.Gln1352His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000587 in 1,614,026 control chromosomes in the GnomAD database, including 18 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar.

• Frequency:
  • Genomes: 𝑓 0.00060 (3 hom., cov: 33)
  • Exomes 𝑓: 0.00059 (15 hom.)
• Consequence: CFTR NM_000492.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4 U:10 B:3
• Conservation: PhyloP100: 2.15

Genes affected

CFTR (HGNC:1884): (CF transmembrane conductance regulator) This gene encodes a member of the ATP-binding cassette (ABC) transporter superfamily. The encoded protein functions as a chloride channel, making it unique among members of this protein family, and controls ion and water secretion and absorption in epithelial tissues. Channel activation is mediated by cycles of regulatory domain phosphorylation, ATP-binding by the nucleotide-binding domains, and ATP hydrolysis. Mutations in this gene cause cystic fibrosis, the most common lethal genetic disorder in populations of Northern European descent. The most frequently occurring mutation in cystic fibrosis, DeltaF508, results in impaired folding and trafficking of the encoded protein. Multiple pseudogenes have been identified in the human genome. [provided by RefSeq, Aug 2017]

ACMG classification

Verdict is Benign. Variant got -7 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_000492.4
• BP4: Computational evidence support a benign effect (MetaRNN=0.015191972).
• BS1: Variant frequency is greater than expected in population eas. gnomad4_exome allele frequency = 0.000586 (857/1461710) while in subpopulation EAS AF= 0.0195 (773/39692). AF 95% confidence interval is 0.0183. There are 15 homozygotes in gnomad4_exome. There are 418 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High Homozygotes in GnomAd at 3 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CFTR	NM_000492.4	c.4056G>C	p.Gln1352His	missense_variant	25/27	ENST00000003084.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CFTR	ENST00000003084.11	c.4056G>C	p.Gln1352His	missense_variant	25/27	1	NM_000492.4	P2

Frequencies

GnomAD3 genomes AF: 0.000611 AC: 93 AN: 152198 Hom.: 3 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.0170

Gnomad SAS AF: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000957

GnomAD3 exomes AF: 0.00102 AC: 257 AN: 251226 Hom.: 3 AF XY: 0.000869 AC XY: 118 AN XY: 135760

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0134

Gnomad SAS exome AF: 0.000196

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000489

GnomAD4 exome AF: 0.000586 AC: 857 AN: 1461710 Hom.: 15 Cov.: 32 AF XY: 0.000575 AC XY: 418 AN XY: 727170

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0195

Gnomad4 SAS exome AF: 0.000220

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00101

GnomAD4 genome AF: 0.000597 AC: 91 AN: 152316 Hom.: 3 Cov.: 33 AF XY: 0.000712 AC XY: 53 AN XY: 74488

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.0166

Gnomad4 SAS AF: 0.000415

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.000947

Alfa AF: 0.000543 Hom.: 1

Bravo AF: 0.000370

ExAC AF: 0.000972 AC: 118

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4 Uncertain:10 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cystic fibrosis Pathogenic:1 Uncertain:4 Benign:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Sep 01, 2023	The p.Q1352H variant (also known as c.4056G>C), located in coding exon 25 of the CFTR gene, results from a G to C substitution at nucleotide position 4056. The glutamine at codon 1352 is replaced by histidine, an amino acid with highly similar properties. The variant has been reported in multiple Asian individuals with CFTR-related findings, including congenital absence of the vas deferens, chronic pancreatitis, and pulmonary disease cohorts; a few individuals were homozygotes and several had additional CFTR variants also detected (Dörk T et al. Hum. Genet., 1997 Sep;100:365-77; Anzai C et al. J. Cyst. Fibros., 2003 Mar;2:14-8; Lee JH et al. Hum. Mol. Genet., 2003 Sep;12:2321-32; Oka H et al. Intern Med, 2010 Jun;49:1251-2; Qiu L et al. Front Med, 2018 Oct;12:550-558; Iso M et al. Hum Genome Var, 2019 Apr;6:17; Yuan P et al. Andrology, 2019 05;7:329-340). In addition, in vitro functional studies showed that this variant results in a 70-80% reduction in the expression of the mature glycosylated CFTR protein and in chloride channel activity (Lee JH et al. Hum. Mol. Genet., 2003 Sep;12:2321-32). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on available evidence to date, this variant is unlikely to be causative of classic cystic fibrosis; however, its contribution to the development of a CFTR-related disorder is uncertain. This alteration is thus classified as a variant of unknown significance. -
Uncertain significance, criteria provided, single submitter	reference population	Soonchunhyang University Bucheon Hospital, Soonchunhyang University Medical Center	Mar 18, 2016	- -
Benign, criteria provided, single submitter	clinical testing	Invitae	Jan 31, 2024	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome Diagnostics Laboratory, The Hospital for Sick Children	May 12, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -
Likely benign, criteria provided, single submitter	clinical testing	Johns Hopkins Genomics, Johns Hopkins University	Sep 07, 2021	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Sep 15, 2003	- -

not provided Pathogenic:1 Uncertain:4

Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Apr 04, 2023	The frequency of this variant in the general population, 0.018 (67/3806 chromosomes in Korean subpopulation, http://gnomad.broadinstitute.org), is higher than would generally be expected for pathogenic variants in this gene. Although the variant has been identified in individuals described as having CF in the published literature (PMIDs: 16596947 (2005), 20558957 (2010), 31136843 (2019), 36409994 (2022)), this variant is likely not associated with classic CF, but it may be associated with CFTR-related diseases such as congenital bilateral absence of the vas deferens (CBAVD) (PMIDs: 28603918 (2017), 30811104 (2019), 32777524 (2021), 34673937 (2021), 35119551 (2022)), bronchiectasis (PMIDs: 12952861 (2003), 29997923 (2018)), and pancreatitis (PMIDs: 16187186 (2005), 32352720 (2020)). In addition, in vitro studies have reported that this variant has a deleterious effect on CFTR protein expression and channel activity (PMID: 12952861 (2003)), however, further research is needed. -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Nov 20, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Oct 11, 2019	The CFTR c.4056G>C; p.Gln1352His variant (rs113857788) has been reported in multiple individuals diagnosed with CFTR-related disorders, such as congenital bilateral absence of vas deferens (Anzai 2003, Danziger 2004, Ratbi 2007, Steiner 2011, Li 2012) and pancreatitis (Lee 2003, Keiles 2006). In multiple affected individuals, this variant has been found in trans to other pathogenic CFTR variants (Anzai 2003, Steiner 2011, Li 2012). It has also been observed at a significantly higher frequency in Asian pancreatitis patients than unaffected individuals (Lee 2003, Fujiki 2004). Expression of the variant protein in a cell line reveals a significant reduction in mature CFTR protein detected compared to wildtype (Lee 2003). The variant is listed in ClinVar (Variation ID: 7237) and is observed in the general population database at a frequency of 0.1% (275/282620 alleles, including three homozygotes) in the Genome Aggregation Database. The glutamine at residue 1352 is highly conserved and computational algorithms (PolyPhen-2, SIFT) predict that the variant is deleterious. Based on available information, the variant is considered to be mildly pathogenic. References: Anzai C et al. CFTR gene mutations in Japanese individuals with congenital bilateral absence of the vas deferens. J Cyst Fibros. 2003 2(1):14-8. Danziger K et al. Improved detection of cystic fibrosis mutations in infertility patients with DNA sequence analysis. Hum Reprod. 2004 19(3):540-6. Fujiki K et al. Genetic evidence for CFTR dysfunction in Japanese: background for chronic pancreatitis. J Med Genet. 2004 41(5):e55. Keiles S et al. Identification of CFTR, PRSS1, and SPINK1 mutations in 381 patients with pancreatitis. Pancreas. 2006 33(3):221-7. Lee J et al. A haplotype-based molecular analysis of CFTR mutations associated with respiratory and pancreatic diseases. Hum Mol Genet. 2003 12(18):2321-32. Li H et al. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) in Chinese patients with congenital bilateral absence of vas deferens. J Cyst Fibros. 2012 11(4):316-23. Ratbi I et al. Detection of cystic fibrosis transmembrane conductance regulator (CFTR) gene rearrangements enriches the mutation spectrum in congenital bilateral absence of the vas deferens and impacts on genetic counselling. Hum Reprod. 2007 22(5):1285-91. Steiner B et al. Common CFTR haplotypes and susceptibility to chronic pancreatitis and congenital bilateral absence of the vas deferens. Hum Mutat. 2011 32(8):912-20. -
Uncertain significance, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	May 09, 2023	PP3, PM3 -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 20, 2022	Published functional studies demonstrate a damaging effect: reduced chloride channel activity and chloride/bicarbonate exchange activity (Lee 2003); Although this variant has not been reported in the homozygous or compound heterozygous state in individuals with cystic fibrosis, it has been reported in individuals of Asian ancestry with CFTR-related disorders (Gallati 2009, Steiner 2011, Cho 2016, Luo 2021); Some case control studies suggest this variant may be associated with pancreatitis in the Asian population (Fujiki 2004, Nakano 2015, Zou 2018, Iso 2019); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 27578509, 21520337, 16678503, 20981092, 20021716, 16187186, 30420730, 25492507, 17719933, 26089335, 28608624, 30450785, 28687971, 15121783, 31180159, 35119551, 12952861, 23514810, 33663443, 32777524, 30992994) -

CFTR-related disorder Pathogenic:2 Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	Jan 18, 2024	The CFTR c.4056G>C variant is predicted to result in the amino acid substitution p.Gln1352His. This variant has been reported in patients with several different phenotypes including asthma, alcoholic chronic pancreatitis, idiopathic chronic pancreatitis, azoospermic males, and bronchiectasis (Cho et al. 2016. PubMed ID: 27578509; Gallati et al. 2009. PubMed ID: 20021716; Kondo et al. 2015. PubMed ID: 26089335; Pall et al. 2007. PubMed ID: 17719933). The c.4056G>C (p.Gln1352His) variant has been found at higher rates in Asian patients with pancreatitis (12.3%) compared to unaffected controls (3.7%) (Fujiki et al. 2004. PubMed ID: 15121783). However, the majority of these studies were conducted in Eastern Asian population cohorts where the c.4056G>C variant is found at a higher allele frequency. Functional studies in CHO cell lines indicate the p.Gln1352His change decreases CFTR protein expression and chloride channel function (Lee et al. 2003. PubMed ID: 12952861; Fujiki et al. 2004. PubMed ID: 15121783; Ngiam et al. 2006. PubMed ID: 16678503). However, no family studies have been conducted to determine if the c.4056G>C variant segregates with disease in individual families and to our knowledge, no homozygous c.4056G>C individuals have been reported with a CFTR-related disorder. This variant has been observed with a minor allele frequency of ~1.3% in East Asians, including 3 homozygous individuals (http://gnomad.broadinstitute.org/variant/7-117304834-G-C). The c.4056G>C has several conflicting interpretations in ClinVar ranging from benign to pathogenic (https://www.ncbi.nlm.nih.gov/clinvar/variation/7237). It is possible that the c.4056G>C variant exhibits incomplete penetrance or is a risk allele for disease. However, without additional conclusive evidence, the clinical significance of this variant remains uncertain. -
Likely pathogenic, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, The Hospital for Sick Children	May 12, 2021	- -
Pathogenic, criteria provided, single submitter	curation	CFTR-France	Jan 29, 2018	- -
Likely benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Dec 04, 2023

Variant summary: CFTR c.4056G>C (p.Gln1352His) results in a non-conservative amino acid change located in the ABC transporter-like and AAA+ ATPase domains of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00066 in 1619220 control chromosomes, predominantly at a frequency of 0.019 within the East Asian subpopulation in the gnomAD database, including 16 homozygotes. The observed variant frequency within East Asian control individuals in the gnomAD database is approximately 1.5 fold of the estimated maximal expected allele frequency for a pathogenic variant in CFTR causing Non-Classic Cystic Fibrosis phenotype (0.013), strongly suggesting that the variant is a benign polymorphism found primarily in populations of East Asian origin. The variant was found with even higher allele frequencies in several East Asian subpopulations, e.g. in the Japanese (with an allele frequency of 0.023 from about 14,000 healthy Japanese individuals in the jMorp database [PMID: 33179747]) and in the Vietnamese (with an allele frequency of 0.05 in 406 unrelated healthy Kinh Vietnamese individuals [PMID: 31180159]), suggesting this variant may be a benign polymorphism found primarily in East Asian populations. On the other hand, the c.4056G>C variant is frequently reported in men with CBAVD in conjunction with a second pathogenic variant, especially the 5T allele. However, one study reported the variant in two unaffected siblings who also carried a pathogenic CFTR mutation in trans (p.Y122X), including an apparently fertile male, suggesting the variant may not be fully penetrant or is not pathogenic (Bienvenu_2005). A recent study found the variant in 32/276 Chinese CAVD patients (i.e. with an allele frequency of 5.98%, including 1 homozygote), and in only 1 allele from 50 control individuals (Luo_2021). This variant is also seen with other phenotypes such as CF, pancreatitis, asthma, nontuberculous mycobacterial lung disease, and bronchiectasis, and the risk association score from several independent publications suggest that this variant is possibly associated with these CF-related phenotypes. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in 10%-30% of normal activity (Lee_2003). The following publications have been ascertained in the context of this evaluation (PMID: 15463840, 16596947, 17539902, 28603918, 9272157, 15121783, 20021716, 29997923, 17003641, 33663443, 31180159, 12952861, 22483971, 32777524, 25492507, 16678503, 20558957, 29520692, 17329263, 33374015, 31682332, 21520337, 28608624, 19812525, 20233062). Fifteen submitters have provided clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as benign/likely benign (n=3), pathogenic/likely pathogenic (n=3) and VUS (n=9). Based on the evidence outlined above, the variant was classified as VUS. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Pathogenic	0.44
Cadd	Benign	22
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;D;.
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.97	D;D;D
MetaRNN	Benign	0.015	T;T;T
MetaSVM	Uncertain	0.77	D
MutationAssessor	Pathogenic	3.4	M;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-4.2	D;D;.
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D;D;.
Sift4G	Pathogenic	0.0010	D;D;.
Polyphen		1.0	D;.;.
Vest4		0.99
MutPred		0.99		Gain of catalytic residue at M1354 (P = 0.0865);.;.;
MVP		1.0
MPC		0.018
ClinPred		0.16	T
GERP RS		3.6
Varity_R		0.94
gMVP		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs113857788; hg19: chr7-117304834; COSMIC: COSV99134274;