chr7-117531002-G-C

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PM2PM5PP2PP3_Strong

The NM_000492.4(CFTR):c.377G>C(p.Gly126Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,626 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. G126D) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

CFTR
NM_000492.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 9.52

Publications

17 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:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PM1

In a domain ABC transmembrane type-1 1 (size 284) in uniprot entity CFTR_HUMAN there are 97 pathogenic changes around while only 7 benign (93%) 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 chr7-117531002-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 53812.Status of the report is reviewed_by_expert_panel, 3 stars.

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, 0.963

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CFTR	NM_000492.4 link	c.377G>C	p.Gly126Ala	missense_variant	Exon 4 of 27	ENST00000003084.11	NP_000483.3	P13569-1A0A024R730

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CFTR	ENST00000003084.11 link	c.377G>C	p.Gly126Ala	missense_variant	Exon 4 of 27	1	NM_000492.4	ENSP00000003084.6		P13569-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152166

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461460

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727038

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33470

American (AMR)

AF:

0.00

AC:

AN:

44634

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26120

East Asian (EAS)

AF:

0.00

AC:

AN:

39682

South Asian (SAS)

AF:

0.00

AC:

AN:

86240

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53384

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5758

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111790

Other (OTH)

AF:

0.00

AC:

AN:

60382

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152166

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74330

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41452

American (AMR)

AF:

0.00

AC:

AN:

15260

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68026

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cystic fibrosis

Uncertain:2

Feb 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 126 of the CFTR protein (p.Gly126Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CFTR-related conditions. ClinVar contains an entry for this variant (Variation ID: 1467947). 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 with a positive predictive value of 80%. This variant disrupts the p.Gly126 amino acid residue in CFTR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 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. -

Feb 17, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.G126A variant (also known as c.377G>C), located in coding exon 4 of the CFTR gene, results from a G to C substitution at nucleotide position 377. The glycine at codon 126 is replaced by alanine, an amino acid with similar properties. 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 internal structural analysis, this variant does not decrease structural stability (Liu F et al. Cell, 2017 03;169:85-95.e8). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not specified

Uncertain:1

Mar 09, 2024

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.377G>C (p.Gly126Ala) results in a non-conservative amino acid change located in the ABC transporter type 1, transmembrane domain (IPR011527) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250898 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.377G>C in individuals affected with Cystic Fibrosis and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 1467947). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.35

BayesDel_addAF

Pathogenic

0.39

BayesDel_noAF

Pathogenic

0.32

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.63

D;.;.;T;.

Eigen

Pathogenic

0.81

Eigen_PC

Pathogenic

0.83

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

D;D;D;D;D

M_CAP

Pathogenic

0.56

MetaRNN

Pathogenic

0.96

D;D;D;D;D

MetaSVM

Uncertain

0.62

MutationAssessor

Benign

1.7

L;.;.;.;L

PhyloP100

9.5

PrimateAI

Uncertain

0.71

PROVEAN

Benign

-1.0

N;.;.;N;.

REVEL

Pathogenic

0.77

Sift

Benign

0.30

T;.;.;T;.

Sift4G

Pathogenic

0.0

D;.;.;D;.

Polyphen

1.0

D;.;.;.;.

Vest4

0.88

MutPred

0.86

Loss of catalytic residue at I125 (P = 0.3083);Loss of catalytic residue at I125 (P = 0.3083);Loss of catalytic residue at I125 (P = 0.3083);Loss of catalytic residue at I125 (P = 0.3083);Loss of catalytic residue at I125 (P = 0.3083);

MVP

1.0

MPC

0.0077

ClinPred

0.77

GERP RS

5.7

Varity_R

0.75

gMVP

0.95

Mutation Taster

=5/95

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over