7-117611763-G-C

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PP2PP3_Strong

The NM_000492.4(CFTR):c.3322G>C(p.Val1108Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000484 in 1,613,080 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V1108I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6O:1

Conservation

PhyloP100: 5.71

Publications

3 publications found

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]

CFTR Gene-Disease associations (from GenCC):

cystic fibrosis
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, Orphanet
congenital bilateral absence of vas deferens
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
hereditary chronic pancreatitis
Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

CFTR links:

ENSG00000083622 (HGNC:40145):

ENSG00000083622 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000492.4

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 197 curated pathogenic missense variants (we use a threshold of 10). The gene has 46 curated benign missense variants. Gene score misZ: -3.1397 (below the threshold of 3.09). Trascript score misZ: -1.0868 (below the threshold of 3.09). GenCC associations: The gene is linked to hereditary chronic pancreatitis, cystic fibrosis, congenital bilateral absence of vas deferens.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.973

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4 link	c.3322G>C	p.Val1108Leu	missense_variant	Exon 20 of 27	ENST00000003084.11	NP_000483.3	P13569-1A0A024R730
CFTR-AS2	NR_199597.1 link	n.177+4466C>G		intron_variant	Intron 2 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11 link	c.3322G>C	p.Val1108Leu	missense_variant	Exon 20 of 27	1	NM_000492.4	ENSP00000003084.6		P13569-1

Frequencies

GnomAD3 genomes

AF:

0.0000264

AC:

AN:

151788

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000589

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

250936

AF XY:

0.0000147

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000353

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000506

AC:

AN:

1461292

Hom.:

Cov.:

AF XY:

0.0000523

AC XY:

AN XY:

726952

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33450

American (AMR)

AF:

0.00

AC:

AN:

44634

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26124

East Asian (EAS)

AF:

0.00

AC:

AN:

39684

South Asian (SAS)

AF:

0.00

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53360

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000666

AC:

AN:

1111656

Other (OTH)

AF:

0.00

AC:

AN:

60368

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.468

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000264

AC:

AN:

151788

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74120

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41320

American (AMR)

AF:

0.00

AC:

AN:

15190

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5178

South Asian (SAS)

AF:

0.00

AC:

AN:

4808

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10550

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000589

AC:

AN:

67964

Other (OTH)

AF:

0.00

AC:

AN:

2082

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000565

Hom.:

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cystic fibrosis

Uncertain:3Other:1

Sep 05, 2021

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Feb 08, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.V1108L variant (also known as c.3322G>C), located in coding exon 20 of the CFTR gene, results from a G to C substitution at nucleotide position 3322. The valine at codon 1108 is replaced by leucine, an amino acid with highly similar properties. This alteration was reported in a 37 year old with CBAVD and no other clinical manifestations of cystic fibrosis; he was also heterozygous for the 11-5T variant, phase not reported (Grangeia A, Genet. Med. 2007 Mar; 9(3):163-72). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Jun 02, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 1108 of the CFTR protein (p.Val1108Leu). This variant is present in population databases (rs397508542, gnomAD 0.004%). This missense change has been observed in individual(s) with a CFTR-related disorder and congenital absence of the vas deferens (PMID: 17413420, 28603918). ClinVar contains an entry for this variant (Variation ID: 53719). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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. -

ClinVar Staff, National Center for Biotechnology Information (NCBI)

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

- -

not specified

Uncertain:1

Jun 30, 2025

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: CFTR c.3322G>C (p.Val1108Leu) results in a conservative amino acid change located in the ABC transporter type 1, transmembrane domain (IPR011527) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 1.6e-05 in 250936 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.3322G>C has been reported in the literature as a non-informative genotype (second allele not-specified) or in cis with a pathogenic CFTR allele in individuals with features of CBAVD or chronic bronchitis (COPDGene study cohort) (example, Grangeia_2007, Steiner_2011, Pagin_2016, Safareli_2022). These reports do not provide unequivocal conclusions about association of the variant with Cystic Fibrosis. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 17413420, 26900683, 34996830, 21520337, 26277102, 29216686). ClinVar contains an entry for this variant (Variation ID: 53719). Based on the evidence outlined above, the variant was classified as uncertain significance. -

CFTR-related disorder

Uncertain:1

Sep 04, 2018

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

not provided

Uncertain:1

May 22, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The CFTR c.3322G>C; p.Val1108Leu variant (rs397508542; ClinVar Variation ID: 53719) is reported in the literature in an individual affected with congenital absence of the vas deferens who also carried a pathogenic-mild CFTR variant (Grangeia 2007), and has been observed in individuals with CFTR-associated conditions, but where the existence of a second allele was not specified (Pagin 2016, Saferali 2022, de Souza 2018). However, it has also been confirmed in cis with severe variants (Steiner 2011 and Claustres 2017). This variant is only observed on four alleles in the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. Computational analyses predict that this variant is deleterious (REVEL: 0.758). Due to conflicting information, the clinical significance of this variant is uncertain at this time. References: Claustres M et al. CFTR-France, a national relational patient database for sharing genetic and phenotypic data associated with rare CFTR variants. Hum Mutat. 2017 Oct;38(10):1297-1315. PMID: 28603918. de Souza DAS et al. Congenital bilateral absence of the vas deferens as an atypical form of cystic fibrosis: reproductive implications and genetic counseling. Andrology. 2018 Jan;6(1):127-135. PMID: 29216686 Grangeia A et al. Molecular characterization of the cystic fibrosis transmembrane conductance regulator gene in congenital absence of the vas deferens. Genet Med. 2007;9(3):163-172. PMID: 17413420 Pagin A et al. Applicability and Efficiency of NGS in Routine Diagnosis: In-Depth Performance Analysis of a Complete Workflow for CFTR Mutation Analysis. PLoS One. 2016 Feb 22;11(2):e0149426. PMID: 26900683 Saferali A et al. CFTR variants are associated with chronic bronchitis in smokers. Eur Respir J. 2022 Aug 10;60(2):2101994. PMID: 34996830 Steiner B et al. Common CFTR haplotypes and susceptibility to chronic pancreatitis and congenital bilateral absence of the vas deferens. Hum Mutat. 2011 Aug;32(8):912-20. PMID: 21520337. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.67

BayesDel_addAF

Pathogenic

0.31

BayesDel_noAF

Pathogenic

0.32

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.63

D;.;.;T;.

Eigen

Pathogenic

0.69

Eigen_PC

Pathogenic

0.70

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

D;D;D;D;D

M_CAP

Pathogenic

0.73

MetaRNN

Pathogenic

0.97

D;D;D;D;D

MetaSVM

Uncertain

0.59

MutationAssessor

Uncertain

2.2

M;.;.;.;.

PhyloP100

5.7

PrimateAI

Uncertain

0.73

PROVEAN

Benign

-1.2

N;.;.;N;.

REVEL

Pathogenic

0.76

Sift

Benign

0.047

D;.;.;D;.

Sift4G

Uncertain

0.0020

D;.;.;D;.

Polyphen

0.98

D;.;.;.;.

Vest4

0.86

MutPred

0.88

Loss of helix (P = 0.0376);.;.;.;.;

MVP

1.0

MPC

0.0044

ClinPred

0.54

GERP RS

5.4

PromoterAI

-0.0046

Neutral

(source)

Varity_R

0.86

gMVP

0.95

Mutation Taster

=10/90

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over