13-20189351-C-T

Position:

chr13-20189351-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_004004.6(GJB2):c.231G>A(p.Trp77Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000103 in 1,614,054 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 Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00011 ( 0 hom. )

Consequence

GJB2
NM_004004.6 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:15O:1

Conservation

PhyloP100: 7.86

Variant links:

Genes affected

GJB2 (HGNC:4284): (gap junction protein beta 2) This gene encodes a member of the gap junction protein family. The gap junctions were first characterized by electron microscopy as regionally specialized structures on plasma membranes of contacting adherent cells. These structures were shown to consist of cell-to-cell channels that facilitate the transfer of ions and small molecules between cells. The gap junction proteins, also known as connexins, purified from fractions of enriched gap junctions from different tissues differ. According to sequence similarities at the nucleotide and amino acid levels, the gap junction proteins are divided into two categories, alpha and beta. Mutations in this gene are responsible for as much as 50% of pre-lingual, recessive deafness. [provided by RefSeq, Oct 2008]

GJB2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 48 pathogenic variants in the truncated region.

PP5

Variant 13-20189351-C-T is Pathogenic according to our data. Variant chr13-20189351-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 17001.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr13-20189351-C-T is described in Lovd as [Pathogenic]. Variant chr13-20189351-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GJB2	NM_004004.6 linkuse as main transcript	c.231G>A	p.Trp77Ter	stop_gained	2/2	ENST00000382848.5	NP_003995.2
GJB2	XM_011535049.3 linkuse as main transcript	c.231G>A	p.Trp77Ter	stop_gained	2/2		XP_011533351.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GJB2	ENST00000382848.5 linkuse as main transcript	c.231G>A	p.Trp77Ter	stop_gained	2/2	1	NM_004004.6	ENSP00000372299	P1
GJB2	ENST00000382844.2 linkuse as main transcript	c.231G>A	p.Trp77Ter	stop_gained	1/1			ENSP00000372295	P1

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152214

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:

0.00124

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000139

AC:

AN:

251384

Hom.:

AF XY:

0.000199

AC XY:

AN XY:

135888

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 SAS exome

AF:

0.00114

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000110

AC:

161

AN:

1461840

Hom.:

Cov.:

AF XY:

0.000165

AC XY:

120

AN XY:

727218

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00182

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74358

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00124

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000256

Hom.:

Bravo

AF:

0.00000756

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.000148

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:15Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:6

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	May 20, 2022	Nonsense variant in the C-terminus predicted to result in protein truncation, as the last 150 amino acids are lost, and other loss-of-function variants have been reported downstream in the Human Gene Mutation Database (HGMD); This variant is associated with the following publications: (PMID: 22975760, 24949729, 19465004, 25087612, 25636251, 24840842, 9139825, 18941476, 29921236, 29542069, 29086887, 30168495, 20086291, 18983339, 31980526, 33614373) -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Feb 28, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	May 08, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 25, 2024	This sequence change creates a premature translational stop signal (p.Trp77) in the GJB2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 150 amino acid(s) of the GJB2 protein. This variant is present in population databases (rs80338944, gnomAD 0.1%). This premature translational stop signal has been observed in individual(s) with autosomal recessive nonsyndromic deafness (PMID: 9139825, 24840842, 25636251). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 17001). This variant disrupts a region of the GJB2 protein in which other variant(s) (p.Lys112Glufs2) have been determined to be pathogenic (PMID: 9529365, 23141775). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

Autosomal recessive nonsyndromic hearing loss 1A

Pathogenic:5Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Foundation for Research in Genetics and Endocrinology, FRIGE's Institute of Human Genetics	Apr 04, 2023	A heterozygous nonsense variant in exon 2 of the GJB2 gene that results in a stop codon and premature truncation of the protein at codon 77 (p.Trp77Ter) was detected. This variant has not been reported in 1000 genomes database and has a minor allele frequency of 0.004%, 0.01%, 0.0008% in the, gnomAD (v3.1), gnomdAD (v2), topmed and databases, respectively. The in silico prediction of the variant is damaging by MuttaionTaster2. The reference codon is conserved across species. In summary, the variant meets our criteria to be classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	3billion	-	The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.014%). The variant is predicted to result in a loss or disruption of normal protein function through protein truncation. Multiple pathogenic variants are reported in the predicted truncated region. The variant has been reported to be in trans with a pathogenic variant as either compound heterozygous or homozygous in at least one similarly affected unrelated individual (PMID: 33187236). The variant has been reported to co-segregate with the disease in at least one similarly affected relative/individual in the same family or similarly affected unrelated family (PMID: 33187236). The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000017001 / PMID: 9139825 / 3billion dataset). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 19, 2018	Variant summary: GJB2 c.231G>A (p.Trp77X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 0.00015 in 246196 control chromosomes. This frequency is not higher than expected for a pathogenic variant in GJB2 causing Autosomal Recessive Non-Syndromic Hearing Loss (0.00015 vs 0.025). c.231G>A has been reported in the literature in multiple individuals affected with Autosomal Recessive Non-Syndromic Hearing Loss in homozygous and compound heterozygous state (e.g. Kelsell 1997, Santos 2005, Mani 2009). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014, and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	May 01, 1997	- -

Hearing loss, autosomal recessive

Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

University of Washington Center for Mendelian Genomics, University of Washington

- -

Autosomal dominant keratitis-ichthyosis-hearing loss syndrome;C0265964:Mutilating keratoderma;C0266004:Knuckle pads, deafness AND leukonychia syndrome;C1835672:Palmoplantar keratoderma-deafness syndrome;C1844678:X-linked mixed hearing loss with perilymphatic gusher;C1865234:Ichthyosis, hystrix-like, with hearing loss;C2673759:Autosomal recessive nonsyndromic hearing loss 1A;C2675750:Autosomal dominant nonsyndromic hearing loss 3A

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Autosomal recessive nonsyndromic hearing loss 1A;C2675235:Autosomal recessive nonsyndromic hearing loss 1B

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

- -

Rare genetic deafness

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jun 22, 2017

The p.Trp77X variant in GJB2 has been reported in several individuals with heari ng loss who were either homozygous or compound heterozygous with a second pathog enic variant in GJB2 (Kelsell 1997, Scott 1998, Rickard 2001, Santos 2005, Mani 2008, Padma 2009, Shafique 2014, LMM data). It has also been identified in 35/30 782 South Asian chromosomes by the genome Aggregation Database (gnomAD, http://g nomad.broadinstitute.org; dbSNP rs80338944), which is consistent with the carrie r frequency for recessive hearing loss in the general population. This nonsense variant leads to a premature termination codon at position 77, which is predicte d to lead to a truncated protein. Loss of function of the GJB2 gene is an establ ished disease mechanism in autosomal recessive nonsyndromic hearing loss. In add ition, another nonsense variant at an adjacent nucleotide position (c.230G>A) re sulting in the same amino acid change has also been reported in many individuals with hearing loss (Hwa 2003, Bazazzagedan 2012, Huang 2015). Several individual s have been reported with the p.Trp77X variant; however, the nucleotide change w as not described (Cheng 2005, Bajaj 2008, Bhalla 2009). In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive hearing l oss based upon the predicted impact of the variant, and homozygosity or compound heterozygosity in multiple affected individuals. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.26

BayesDel_noAF

Pathogenic

0.54

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.97

Eigen_PC

Pathogenic

0.85

FATHMM_MKL

Pathogenic

0.97

MutationTaster

Benign

1.0

A;A

Vest4

0.92

GERP RS

5.3

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

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

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over