rs397508137

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 7P and 1B. PM1PM2PM5PP5BP4

The NM_000492.4(CFTR):​c.1001G>A​(p.Arg334Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000185 in 1,614,010 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R334L) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00019 ( 0 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

8
5
6

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:12U:6

Conservation

PhyloP100: 7.60
Variant links:
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1
In a helix (size 18) in uniprot entity CFTR_HUMAN there are 16 pathogenic changes around while only 2 benign (89%) in NM_000492.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr7-117540231-G-T is described in Lovd as [Pathogenic].
PP5
Variant 7-117540231-G-A is Pathogenic according to our data. Variant chr7-117540231-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 53159.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=6, Pathogenic=2, Likely_pathogenic=8}. Variant chr7-117540231-G-A is described in Lovd as [Likely_pathogenic].
BP4
Computational evidence support a benign effect (MetaRNN=0.31236058). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CFTRNM_000492.4 linkc.1001G>A p.Arg334Gln missense_variant Exon 8 of 27 ENST00000003084.11 NP_000483.3 P13569-1A0A024R730

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CFTRENST00000003084.11 linkc.1001G>A p.Arg334Gln missense_variant Exon 8 of 27 1 NM_000492.4 ENSP00000003084.6 P13569-1

Frequencies

GnomAD3 genomes
AF:
0.0000921
AC:
14
AN:
152044
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000656
Gnomad ASJ
AF:
0.00173
Gnomad EAS
AF:
0.000192
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000588
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.000111
AC:
28
AN:
251222
Hom.:
0
AF XY:
0.000103
AC XY:
14
AN XY:
135766
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000868
Gnomad ASJ exome
AF:
0.000893
Gnomad EAS exome
AF:
0.0000544
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000114
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000194
AC:
284
AN:
1461848
Hom.:
0
Cov.:
31
AF XY:
0.000198
AC XY:
144
AN XY:
727220
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000671
Gnomad4 ASJ exome
AF:
0.00126
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.0000812
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.000203
Gnomad4 OTH exome
AF:
0.000232
GnomAD4 genome
AF:
0.0000920
AC:
14
AN:
152162
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74390
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.00173
Gnomad4 EAS
AF:
0.000193
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000588
Gnomad4 OTH
AF:
0.000473
Alfa
AF:
0.000163
Hom.:
0
Bravo
AF:
0.000121
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.000140
AC:
17
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.000109
EpiControl
AF:
0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:12Uncertain:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Cystic fibrosis Pathogenic:4Uncertain:3
Sep 29, 2023
Ambry Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.R334Q variant (also known as c.1001G>A), located in coding exon 8 of the CFTR gene, results from a G to A substitution at nucleotide position 1001. The arginine at codon 334 is replaced by glutamine, an amino acid with highly similar properties. This variant has been detected in conjunction with a pathogenic mutation in multiple individuals with intermediate sweat chloride levels and/or CFTR-related disorders, as well as seeming healthy adults (Dayangaç D et al. Hum Reprod, 2004 May;19:1094-100; Picci L et al. J Cyst Fibros, 2010 Jan;9:29-35; Behar DM et al. Mol Genet Genomic Med, 2017 May;5:223-236; Munck A et al. Pediatr Pulmonol, 2020 04;55:918-928; Ambry internal data). Although this variant did not completely abolish CFTR function, it impaired CFTR function significantly (Gong X et al. Arch. Biochem. Biophys., 2004 Jun;426:78-82; Linsdell P. Biochim Biophys Acta, 2015 Jul;1848:1573-90; Han ST et al. JCI Insight, 2018 07;3: Raraigh KS et al. Am J Hum Genet, 2018 06;102:1062-1077). In addition, the alteration has been reported as a variant of varying clinical consequences (VVCC) (Sosnay PR et al. Nat. Genet., 2013 Oct;45:1160-7; The Clinical and Functional TRanslation of CFTR (CFTR2); available at http://cftr2.org. Accessed August 23, 2022). 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, it likely contributes to the development of a CFTR-related disorder. This alteration is thus classified as likely pathogenic. -

Dec 11, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: CFTR c.1001G>A (p.Arg334Gln) results in a conservative amino acid change located in the ABC transporter type 1, transmembrane domain (IPR011527) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. Several computational tools predict a significant impact on normal splicing: Three predict the variant creates a cryptic 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00011 in 251222 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in CFTR causing Cystic Fibrosis (0.00011 vs 0.013), allowing no conclusion about variant significance. c.1001G>A has been reported in the literature in the compound heterozygous state together with a pathogenic variant (p.Trp1282X, F508del) in multiple individuals affected with Cystic Fibrosis, although often these individuals have atypical CF with intermmediate sweat chloride levels and/or a mild phenotype (e.g. Behar_2017, Munck_2020, McCague_2019). It has also been found in at least two individuals with CBAVD, one of whom was compound heterozygous together with a pathogenic CFTR variant (p.Arg347His) (e.g. Dayangac_2004, Havasi_2010). However, the variant has also been reported together with a pathogenic variant (p.Arg553X) in a 38 year old male patient without CF, CBAVD, or other CFTR-related conditions (Picci_2010), suggesting it may have low penetrance. Several publications report experimental evidence evaluating an impact on protein function (e.g. Smith_2001, Broadbent_2015, Wang_2016, Han_2018, Raraigh_2018). At least two studies showed this variant results in approximately 20-30% chloride channel function compared to the WT protein (Han_2018, Raraigh_2018, Bihler_2024). Additionally, other missense variants at the same codon, R334W and R334L, have been classified as pathogenic suggesting the arginine residue is important for CFTR protein function. Having been observed in individuals with CF/ atypical CF, CFTR-related disorders, and healthy individuals, and due to its level of activity versus the WT, this variant has been described as having variable clinical consequences (e.g. Raraigh_2018). The following publications have been ascertained in the context of this evaluation (PMID: 28546993, 21228398, 33572515, 25277268, 22439019, 15070876, 26493493, 30046002, 20100616, 17440499, 11379874, 25892339, 34405919, 16126774, 31916691, 19897426, 34782259, 11585852, 27175795, 30888834, 29805046, 38388235). ClinVar contains an entry for this variant (Variation ID: 53159). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Oct 13, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 334 of the CFTR protein (p.Arg334Gln). This variant is present in population databases (rs397508137, gnomAD 0.09%). This missense change has been observed in individual(s) with typical or atypical cystic fibrosis. Also, it has been identified in unaffected individuals as well as an individual affected with congenital bilateral absence of the vas deferens who also had one known pathogenic mutation in CFTR (PMID: 11379874, 15070876, 16126774, 19897426, 28546993). ClinVar contains an entry for this variant (Variation ID: 53159). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CFTR protein function. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on CFTR function (PMID: 12679372, 15130785, 17673962, 22612315, 25277268, 25892339). This variant disrupts the p.Arg334 amino acid residue in CFTR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15371902, 23974870). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Jul 22, 2021
Genome-Nilou Lab
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 25, 2017
Counsyl
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 01, 2024
Laboratory of Medical Genetics, National & Kapodistrian University of Athens
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: curation

- -

Apr 08, 2020
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not provided Pathogenic:3Uncertain:2
Aug 01, 2017
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jun 13, 2017
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The CFTR c.1001G>A, p.Arg334Gln variant (rs397508137) has been described in the literature in individuals with atypical cystic fibrosis as well as seemingly healthy adults (Dayangac 2004, Picci 2010). However functional studies have shown this variant to cause a disruption of anion interactions with the CFTR pore (Gong 2003, Linsdell 2015, Smith 2001, Zhou 2007), resulting in reduced chloride conductance (Gong 2004). Other missense variants at this residue have also been implicated in affecting CFTR protein functions (Gong 2003, Gong 2004, Smith 2001, Sosnay 2013, Zhou 2007). The p. Arg334Gln variant is listed in ClinVar (Variation ID: 53159), and observed in the general population databases at a frequency of 0.02 percent in the 1000 Genomes Project, and 0.01 percent in the Exome Aggregation Consortium. The arginine at residue 334 is highly conserved, but computational algorithms (Align GVGD: c0; Mutation Taster: disease-causing; PolyPhen-2: probably damaging; SIFT: tolerated) are inconclusive on the variant's impact on the protein. Based on the above information, the variant is classified as likely pathogenic. References: Dayangac D et al. Mutations of the CFTR gene in Turkish patients with congenital bilateral absence of the vas deferens. Hum Reprod. 2004; 19(5):1094-100. Gong X et al. Molecular determinants and role of an anion binding site in the external mouth of the CFTR chloride channel pore. J Physiol. 2003; 549(Pt 2):387-97. Gong X et al. Maximization of the rate of chloride conduction in the CFTR channel pore by ion-ion interactions. Arch Biochem Biophys. 2004; 426(1):78-82. Linsdell P. Interactions between permeant and blocking anions inside the CFTR chloride channel pore. Biochim Biophys Acta. 2015; 1848(7):1573-90. Picci L et al. A 10-year large-scale cystic fibrosis carrier screening in the Italian population. J Cyst Fibros. 2010; 9(1):29-35. Smith S et al. CFTR: covalent and noncovalent modification suggests a role for fixed charges in anion conduction. J Gen Physiol. 2001; 118(4):407-31. Sosnay PR et al. Defining the disease liability of variants in the cystic fibrosis transmembrane conductance regulator gene. Nat Genet. 2013; 45(10):1160-7. Zhou J et al. Direct and indirect effects of mutations at the outer mouth of the cystic fibrosis transmembrane conductance regulator chloride channel pore. J Membr Biol. 2007; 216(2-3):129-42. -

Mar 19, 2025
GeneDx
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Classified as a variant of varying clinical consequence in a well-curated database (CFTR2); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 23974870, 11379874, 15070876, 11427889, 30046002, 25892339, 9922375, 20100616, 16126774, 35451201, 34782259, 32357917, 21228398, 17673962, 15371902, 25277268, 11585852, 15130785, 22612315, 27175795, 29805046, 12679372, 30146269, 34426522, 32773111, 34405919, 36207272, 33444622, 19897426, 11180668, 17440499, 28546993, 32784480, 33572515, 31916691, 36969284, 36670555, 34888852, 38515211, 34996830, 36428953, 37628659, 36910284, 27086061, 19669005, 30134826, 38388235, 37823914, 37888495, 39841779, 39262237) -

Jul 13, 2021
Mayo Clinic Laboratories, Mayo Clinic
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jun 17, 2023
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The CFTR c.1001G>A (p.Arg334Gln) variant has been reported in the published literature in individuals with congenital bilateral absence of the vas deferens (PMID: 15070876 (2004), 16126774 (2005), and 20100616 (2010)) and Cystic Fibrosis (PMID: 28546993 (2017), 31916691 (2020)). This variant was also found in unaffected individuals, one of whom also carried a pathogenic CFTR variant (PMID: 11379874 (2001) and 19897426 (2010)). Functional studies have shown this variant disrupts anion binding at the CFTR channel pore, but with inconclusive effects on chloride-stimulated conductance (PMID: 12679372 (2003), 17673962 (2007), 25892339 (2015), and 25277268 (2015)). This variant was found to have a modest response to CFTR modulators (PMID: 30046002 (2018)). The frequency of this variant in the general population, 0.0022 (6/2668 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -

CFTR-related disorder Pathogenic:2Uncertain:1
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Jul 30, 2024
PreventionGenetics, part of Exact Sciences
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

The CFTR c.1001G>A variant is predicted to result in the amino acid substitution p.Arg334Gln. This variant has been shown to weaken CFTR channel function and has been reported in patients with congenital bilateral absence of vas deferens (Li et al. 2012. PubMed ID: 22612315; Dayangac et al. PubMed ID: 15070876; Morea et al. 2005. PubMed ID: 16126774). This variant is reported in 0.096% of alleles in individuals of Ashkenazi Jewish descent in gnomAD. Another missense change at the same amino acid position (p.Arg334Trp) has previously been reported to be causative for cystic fibrosis (see supplemental table 2 in Sosnay et al. 2013. PubMed ID: 23974870). This variant is interpreted as likely pathogenic. -

Apr 08, 2020
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Cystic fibrosis;C0238339:Hereditary pancreatitis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation;C2749757:Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
Apr 27, 2024
Fulgent Genetics, Fulgent Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
Mar 30, 2024
Baylor Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Cystic fibrosis;C5924204:CFTR-related disorder Pathogenic:1
Jul 01, 2022
CFTR-France
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: curation

when the variant is in trans with another CF-causing variation, can either result in CF or in a CFTR-RD -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.39
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Pathogenic
0.28
CADD
Pathogenic
26
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.47
T;.;.;T;.
Eigen
Uncertain
0.20
Eigen_PC
Benign
0.15
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.98
D;D;D;D;D
M_CAP
Pathogenic
0.30
D
MetaRNN
Benign
0.31
T;T;T;T;T
MetaSVM
Uncertain
0.37
D
MutationAssessor
Benign
1.1
L;.;.;.;L
PrimateAI
Uncertain
0.60
T
PROVEAN
Benign
-0.33
N;.;.;N;.
REVEL
Pathogenic
0.69
Sift
Benign
0.18
T;.;.;T;.
Sift4G
Pathogenic
0.0
D;.;.;D;.
Polyphen
1.0
D;.;.;.;.
Vest4
0.60
MVP
0.99
MPC
0.0039
ClinPred
0.23
T
GERP RS
4.5
Varity_R
0.25
gMVP
0.86

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs397508137; hg19: chr7-117180285; COSMIC: COSV50078148; API