13-20189546-AC-ACC

Variant summary

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

The NM_004004.6(GJB2):​c.35_36insG​(p.Val13CysfsTer35) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000151 in 1,461,606 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. G12G) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

GJB2
NM_004004.6 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:15

Conservation

PhyloP100: 7.85
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]

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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 267 pathogenic variants in the truncated region.
PP5
Variant 13-20189546-A-AC is Pathogenic according to our data. Variant chr13-20189546-A-AC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 94392.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
GJB2NM_004004.6 linkuse as main transcriptc.35_36insG p.Val13CysfsTer35 frameshift_variant 2/2 ENST00000382848.5
GJB2XM_011535049.3 linkuse as main transcriptc.35_36insG p.Val13CysfsTer35 frameshift_variant 2/2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
GJB2ENST00000382848.5 linkuse as main transcriptc.35_36insG p.Val13CysfsTer35 frameshift_variant 2/21 NM_004004.6 P1
GJB2ENST00000382844.2 linkuse as main transcriptc.35_36insG p.Val13CysfsTer35 frameshift_variant 1/1 P1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.0000241
AC:
6
AN:
249362
Hom.:
0
AF XY:
0.0000296
AC XY:
4
AN XY:
134954
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000109
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000896
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000151
AC:
22
AN:
1461606
Hom.:
0
Cov.:
32
AF XY:
0.0000124
AC XY:
9
AN XY:
727100
show subpopulations
Gnomad4 AFR exome
AF:
0.0000597
Gnomad4 AMR exome
AF:
0.000112
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000756
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000989
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.0000151
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:15
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:7
Pathogenic, criteria provided, single submitterclinical testingInstitute of Medical Genetics and Applied Genomics, University Hospital TübingenFeb 01, 2021- -
Pathogenic, criteria provided, single submitterclinical testingKnight Diagnostic Laboratories, Oregon Health and Sciences UniversityNov 23, 2016- -
Pathogenic, criteria provided, single submitterclinical testingInvitaeJan 11, 2024This sequence change creates a premature translational stop signal (p.Val13Cysfs*35) in the GJB2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 214 amino acid(s) of the GJB2 protein. This variant is present in population databases (rs398123814, gnomAD 0.01%). This premature translational stop signal has been observed in individuals with autosomal recessive deafness (PMID: 11439000, 18519481, 19366456, 20497192, 23638949, 24503448). It has also been observed to segregate with disease in related individuals. This variant is also known as 35insG. ClinVar contains an entry for this variant (Variation ID: 94392). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingAthena DiagnosticsJan 10, 2023This variant is expected to result in the loss of a functional protein. The frequency of this variant in the general population is consistent with pathogenicity. (Genome Aggregation Database (gnomAD), Cambridge, MA (URL: http://gnomad.broadinstitute.org)) In multiple individuals with nonsyndromic hearing loss, this variant has been seen with a single recessive pathogenic variant in the same gene. In some published literature, this variant is referred to as c.35insG. -
Pathogenic, criteria provided, single submitterclinical testingGeneDxOct 27, 2022Frameshift variant predicted to result in protein truncation, as the last 214 amino acids are replaced with 34 different amino acids, 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: 9482292, 29754767, 31589614, 31541171, 29871260, 32645618, 31160754, 34416374, 23638949, 20639189, 24503448) -
Pathogenic, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Aug 28, 2012- -
Pathogenic, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenNov 01, 2023- -
Autosomal recessive nonsyndromic hearing loss 1A Pathogenic:5
Pathogenic, no assertion criteria providedclinical testingWangQJ Lab, Chinese People's Liberation Army General HospitalJul 01, 2021- -
Likely pathogenic, criteria provided, single submitterliterature onlyCounsylFeb 05, 2015- -
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpFeb 09, 2021Variant summary: GJB2 c.35dupG (p.Val13CysfsX35) results in a premature termination codon, predicted to cause a truncation, which is a commonly known mechanism for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 2.4e-05 in 249362 control chromosomes (gnomAD). c.35dupG has been reported in the literature in several individuals affected with Autosomal Recessive Non-Syndromic Hearing Loss (e.g. Rabionet_2000, D'Andrea_2002, Dai_2009, Hjelm_2010, Godbole_2010, Bazazzadegan_2012, Usami_2012, Banjara_2015, Liu_2020). 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. Eight other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, no assertion criteria providedcase-controlGenetic Testing Center for Deafness, Department of Otolaryngology Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General HospitalFeb 26, 2019- -
Pathogenic, no assertion criteria providedclinical testingNatera, Inc.Oct 24, 2020- -
Hearing loss Pathogenic:1
Pathogenic, no assertion criteria providedclinical testingClinical Molecular Genetics Laboratory, Johns Hopkins All Children's HospitalJan 22, 2009- -
Hearing impairment Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingDepartment of Otolaryngology – Head & Neck Surgery, Cochlear Implant CenterApr 12, 2021PVS1_Strong, PM2_Moderate, BP5_Supporting -
Rare genetic deafness Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineNov 30, 2016The p.Val13fs variant in GJB2, also reported as c.35dupG or c.35insG, has been r eported in >5 individuals with hearing loss who were compound heterozygous for a second pathogenic variant in GJB2 (Estivill 1998, Huang 2014, Snoeckx 2005, Tsu kada 2010). It has been identified in 6/250260 of the total chromosomes in the genome Aggregation Database (http://gnomad.broadinstitute.org/, dbSNP rs39812381 4). This low frequency in the general population is consistent with the carrier frequency for autosomal recessive hearing loss. This variant is predicted to ca use a frameshift, which alters the protein?s amino acid sequence beginning at po sition 13 and leads to a premature termination codon 35 amino acids downstream. In summary, this variant meets criteria to be classified as pathogenic for autos omal recessive hearing loss based on the predicted impact to the protein and mul tiple previously reported affected compound heterozygotes. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

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.

Other links and lift over

dbSNP: rs80338939; hg19: chr13-20763685; API