rs80338939

chr13-20189546-AC-Achr13-20189546-AC-ACC

Variant summary

Our verdict is Pathogenic. Variant got 6 ACMG points: 14P and 8B. PVS1 PM3 BA1 PS4

This summary comes from the ClinGen Evidence Repository: The c.35delG variant in GJB2 is predicted to cause a premature stop codon in biologically-relevant-exon 2/2 that leads to a truncated or absent protein in a gene in which loss-of-function is an established mechanism (PVS1). This variant has been detected in patients with hearing loss in trans with at least 4 pathogenic or suspected-pathogenic variants (PM3_VS; PMID:26445815). This variant was found to have a statistically higher prevalence in affected individuals over controls (PS4; PMID:26969326, 25999548). The filtering allele frequency of the c.35delG variant in the GJB2 gene is 0.9% for European (Non-Finnish) chromosomes in the Genome Aggregation Database (1207/124552 with 95% CI), which is a high enough frequency to be classified as benign based on thresholds defined by the ClinGen Hearing Loss Expert Panel for autosomal recessive hearing loss variants (BA1). The ClinGen Hearing Loss Expert Panel believes that the evidence for the pathogenicity of this variant for hearing loss outweighs the high allele frequency of the variant in population databases. Therefore, the BA1 code will not contribute to the overall classification. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive non-syndromic hearing loss based on the ACMG/AMP criteria applied, as specified by the Hearing Loss Expert Panel: PVS1, PM3_VS, PS4, BA1. LINK:https://erepo.genome.network/evrepo/ui/classification/CA127023/MONDO:0019497/005

• Frequency:
  • Genomes: 𝑓 0.0063 (4 hom., cov: 32)
  • Exomes 𝑓: 0.0071 (34 hom.)
• Consequence: GJB2 NM_004004.6 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:82 O:2
• Conservation: PhyloP100: 7.85

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]

ACMG classification

Verdict is Pathogenic. Variant got 6 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GJB2	NM_004004.6	c.35del	p.Gly12ValfsTer2	frameshift_variant	2/2	ENST00000382848.5
GJB2	XM_011535049.3	c.35del	p.Gly12ValfsTer2	frameshift_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GJB2	ENST00000382848.5	c.35del	p.Gly12ValfsTer2	frameshift_variant	2/2	1	NM_004004.6	P1
GJB2	ENST00000382844.2	c.35del	p.Gly12ValfsTer2	frameshift_variant	1/1			P1

Frequencies

GnomAD3 genomes AF: 0.00627 AC: 952 AN: 151764 Hom.: 4 Cov.: 32

Gnomad AFR AF: 0.00124

Gnomad AMI AF: 0.00219

Gnomad AMR AF: 0.00584

Gnomad ASJ AF: 0.00403

Gnomad EAS AF: 0.000194

Gnomad SAS AF: 0.000833

Gnomad FIN AF: 0.00956

Gnomad MID AF: 0.00633

Gnomad NFE AF: 0.00980

Gnomad OTH AF: 0.0106

GnomAD3 exomes AF: 0.00597 AC: 1488 AN: 249362 Hom.: 7 AF XY: 0.00599 AC XY: 808 AN XY: 134954

Gnomad AFR exome AF: 0.00117

Gnomad AMR exome AF: 0.00480

Gnomad ASJ exome AF: 0.00318

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000817

Gnomad FIN exome AF: 0.00808

Gnomad NFE exome AF: 0.00920

Gnomad OTH exome AF: 0.00718

GnomAD4 exome AF: 0.00713 AC: 10423 AN: 1461600 Hom.: 34 Cov.: 32 AF XY: 0.00701 AC XY: 5100 AN XY: 727098

Gnomad4 AFR exome AF: 0.00128

Gnomad4 AMR exome AF: 0.00494

Gnomad4 ASJ exome AF: 0.00356

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000592

Gnomad4 FIN exome AF: 0.00947

Gnomad4 NFE exome AF: 0.00818

Gnomad4 OTH exome AF: 0.00652

GnomAD4 genome AF: 0.00627 AC: 952 AN: 151882 Hom.: 4 Cov.: 32 AF XY: 0.00601 AC XY: 446 AN XY: 74244

Gnomad4 AFR AF: 0.00123

Gnomad4 AMR AF: 0.00583

Gnomad4 ASJ AF: 0.00403

Gnomad4 EAS AF: 0.000194

Gnomad4 SAS AF: 0.000833

Gnomad4 FIN AF: 0.00956

Gnomad4 NFE AF: 0.00980

Gnomad4 OTH AF: 0.0104

Alfa AF: 0.00556 Hom.: 0

Bravo AF: 0.00549

EpiCase AF: 0.00916

EpiControl AF: 0.00842

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:82 Other:2

Revision: reviewed by expert panel

Submissions by phenotype

Autosomal recessive nonsyndromic hearing loss 1A Pathogenic:31 Other:1

Pathogenic, flagged submission	clinical testing	Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia	May 09, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Knight Diagnostic Laboratories, Oregon Health and Sciences University	Mar 14, 2016	The c.35delG (p.Gly12Valfs*2) frameshift variant introduces a premature stop codon, leading to the truncation of the Connexin 26 protein. The c.35delG variant represents the most common pathogenic variant in Caucasian patients with genetic sensorineural deafness (Carrasquillo et al. 1997; Denoyelle et al. 1997; Zelante et al. 1997; Green et al. 1999; Gasparini et al. 2000; Kenneson et al. 2002; Bouwer et al. 2007). Therefore, this collective evidence supports the classification of the c.35delG (p.Gly12Valfs*2) as a Pathogenic variant for Nonsyndromic hearing loss. -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratory of Medical Genetics, National & Kapodistrian University of Athens	Jun 26, 2018	PVS1, PS3, PM1, PP5 -
Pathogenic, criteria provided, single submitter	clinical testing	Center of Genomic medicine, Geneva, University Hospital of Geneva	Nov 08, 2018	This variant was identified in compound heterozygosity with a second variant in GJB2 in 2 different male patients with congenital bilateral moderate hearing loss. -
Pathogenic, criteria provided, single submitter	clinical testing	Integrating Genomics into Medicine, Frazer Institute, University Of Queensland	Jun 02, 2023	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Oct 05, 2012	- -
Pathogenic, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Jul 18, 2022	- -
Pathogenic, no assertion criteria provided	clinical testing	Diagnostics Centre, Carl Von Ossietzky University Oldenburg	Nov 08, 2023	The variant GJB2: c.35delG, p.Gly12Valfs*2, which is located in the coding exon 2 of the GJB2 gene, results from a deletion of a base at nucleotide position c.35. The variant causes a frameshift that results in the replace of a glycine by a valine at protein position 12, followed by a premature translation stop codon after two amino acids. Degradation of the truncated gene product due to non-sense mediated decay is not predicted. However, a large part of the protein is lost, including the functionally relevant connexin domain.The variant was described in an Italian study as the most common GJB2 variant associated with autosomal recessive non-syndromic hearing loss (PMID: 12176036). Multiple studies showed an increased prevalence on individuals affected with hearing loss (PMID: 26969326, 25999548). A cell culture-based functional study showed that the altered gene product is no longer detectable and leads to a loss of function of GJB2 (PMID: 12176036). The variant is not considered rare in the overall population (allele frequency= 0.007050 in gnomAD, v4.1.0). The variant has been consistently classified as Pathogenic in more than 80 entries in ClinVar (ClinvarID: 17004). The ClinGen Expert panel for hearing disorders classified this variant as Pathogenic despite the comparatively high allele frequency. In summary, the variant is classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics Munich, Klinikum Rechts Der Isar, TU München	Sep 28, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein	Jan 10, 2023	ACMG classification criteria: PVS1 very strong, PS4 strong, PM3 very strong -
not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Jun 20, 2017	A homozygous deletion variant was identified, NM_004004.5(GJB2):c.35delG in exon 2 of the GJB2 gene.This deletion creates a frameshift from amino acid position 12, introducing a stop codon 2 residues downstream, NP_003995.2(GJB2):p.(Gly12Valfs*2). This results in loss of protein function through truncation (majority of the protein).This variant is present in the gnomAD population database at a frequency of 0.6%. It has been previously reported to be the most common pathogenic variant in deaf individuals with European ancestry (ClinVar). In addition, other truncating variants downstream of c.35delG in GJB2 have been reported as pathogenic in individuals with deafness (ClinVar). Based on current information, this variant has been classified as PATHOGENIC. -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Oct 18, 2019	NM_004004.5(GJB2):c.35delG(aka p.G12Vfs*2) is classified as pathogenic in the context of GJB2-related DFNB1 nonsyndromic hearing loss and deafness. Sources cited for classification include the following: PMID 12176036, 24158611, 19371219, 15967879, 16380907. Classification of NM_004004.5(GJB2):c.35delG(aka p.G12Vfs*2) is based on the following criteria: The variant causes a premature termination codon that is not expected to be targeted by nonsense-mediated mRNA decay; however, literature evidence strongly supports pathogenicity. Please note: this variant was assessed in the context of healthy population screening. -
Pathogenic, no assertion criteria provided	clinical testing	Zotz-Klimas Genetics Lab, MVZ Zotz Klimas	Nov 24, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Equipe Genetique des Anomalies du Developpement, Université de Bourgogne	Oct 28, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Daryl Scott Lab, Baylor College of Medicine	Feb 01, 2022	- -
Pathogenic, no assertion criteria provided	case-control	Genetic Testing Center for Deafness, Department of Otolaryngology Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital	Feb 26, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genomic Research Center, Shahid Beheshti University of Medical Sciences	Aug 07, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 19, 2021	We found this variant in a patient with hearing impairment in a homozygous state. -
Pathogenic, criteria provided, single submitter	clinical testing	Genetics and Molecular Pathology, SA Pathology	May 11, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genetics Laboratory, Skane University Hospital Lund	Jun 20, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Dec 04, 2018	The GJB2 c.35delG (p.Gly12ValfsTer2) variant, which results in a frameshift and is predicted to result in premature termination of the protein, is one of the most common variants associated with the recessive form of nonsyndromic hearing loss, DFNB1, with more than half of all persons of northern European ancestry with two identifiable GJB2 mutations being homozygous for this variant (Scott et al. 1998). Across a small selection of the available literature, the p.Gly12ValfsTer2 variant has been identified in a homozygous state in 89 individuals with hearing loss, in a compound heterozygous state in 23 affected individuals, and in a heterozygous state in 11 affected individuals in whom a second variant was not identified (Zelante et al. 1997; Estivill et al. 1998; Murgia et al. 1999; Snoeckx et al. 2005). The p.Gly12ValfsTer2 variant was identified in a total of ten of 800 control chromosomes and is reported at a frequency of 0.0152 in the Utah residents with Northern and Western European ancestry population of the 1000 Genomes Project which is consistent with the carrier frequency for p.Gly12ValfsTer2 (Snoeckx et al. 2005). Based on the potential impact of frameshift variants and the evidence from the literature the p.Gly12ValfsTer2 variant is classified as pathogenic for recessive nonsyndromic hearing loss. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -
Pathogenic, no assertion criteria provided	research	Division of Human Genetics, Children's Hospital of Philadelphia	Mar 20, 2015	The GJB2 variant (c.35delG, p.Gly12Valfs*2) identified in this patient is a frameshift variant, reported to be the most common pathogenic variant in individuals with European ancestry (Carrasquillo et al. 1997, PMID: 9328482; Denoyelle et al. 1997, PMID: 9336442; Zelante et al. 1997, PMID: 9285800; Green et al. 1999, PMID: 10376574; Gasparini et al. 2000, PMID: 10713883; Kenneson et al. 2002, PMID: 12172392; Bouwer et al. 2007, PMID: 18294064). -
Pathogenic, criteria provided, single submitter	clinical testing	3billion	Jan 03, 2022	Frameshift: 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 (PVS1_S). Functional studies provide strong evidence of the variant having a damaging effect on the gene or gene product (PMID: 12176036, PS3_S). The variant has been observed in multiple (>3) similarly affected unrelated individuals(PMID: 25999548, 26969326, PS4_S). The variant has been reported multiple times as an established pathogenic/likely pathogenic variant (ClinVar ID: VCV000017004, PMID:9285800, 3billion dataset). The same variant was previously reported several times in trans with another pathogenic variant in this gene (PMID: 26445815, PM3_VS). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center	Mar 26, 2024	- -
Pathogenic, criteria provided, single submitter	research	UAEU Genomics Laboratory, United Arab Emirates University	Mar 23, 2022	The frameshift deletion NM_004004.6(GJB2):c.35delG (p.Gly12Valfs*2) is reported to be the most common pathogenic variant in GJB2 associated with Autosomal Recessive Deafness 1A (DFNB1A) across different ethnic groups and reported in homozygous and compound heterozygous states (PubMed: 9285800, 10422812, 10713883, 11313751, 11483639, 26445815). This variant has been curated as Pathogenic by ClinGen hearing loss Expert panel members (PMID: 30311386). Though this variant is observed in 1027/111668 (0.92%) alleles in the gnomAD database, studies suggests that the carrier frequency of this variant can reach up to 2%-4% (PMID: 16380907). The p.Gly12Valfs*2 variant is predicted to cause loss of normal protein function through protein truncation caused a frameshift mutation. Published in vitro functional studies demonstrated that the variation leads to the absence of functional protein and activity (PubMed: 12176036). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics, University of Leipzig Medical Center	Jun 20, 2023	Criteria applied: PM3_VSTR,PVS1_STR -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 08, 2017	Variant summary: The GJB2 c.35delG (p.Gly12Valfs) variant results in a premature termination codon, predicted to cause a truncated or absent GJB2 protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory (e.g., c.71G>A [p.Trp24X], c.131G>A [p.Trp44X], and c.167delT [p.Leu56fs). This variant was found in 733/122042 control chromosomes (3 homozygotes) including ExAC at a frequency of 0.0060061, which does not exceed the estimated maximal expected allele frequency of a pathogenic GJB2 variant (0.025). This variant is known to be the most common pathogenic GJB2 variant worldwide that causes autosomal recessive nonsyndromic hearing loss. Immunochemistry studies showed that the variant does not produce detectable protein and prevents normal intercellular molecular transfer (D'Andrea_BBRC_2002). Multiple clinical diagnostic laboratories/reputable databases have classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, no assertion criteria provided	clinical testing	Clinical Genomics Program, Stanford Medicine	Jun 24, 2021	The p.Gly12Valfs*2 variant in the GJB2 gene is a well reported cause of nonsyndromic hearing loss. This variant was determined to be in trans with other pathogenic variants (p.Val37Ile, p.Met34Thr), consistent with autosomal recessive inheritance (Sloan-Heggen et al., 2016). The presence of this variant with an established disease-causing variant on the opposite allele increases suspicion for its pathogenicity. The p.Gly12Valfs*2 variant has also been identified in 1,217/127,068 European chromosomes by the Genome Aggregation Database (http://gnomad.broadinstitute.org/). Although this variant has been seen in the general population, its frequency is consistent with a recessive carrier frequency for hearing loss. This variant results in a 1 bp deletion, which causes a shift in the protein reading frame, leading to a premature termination codon 2 amino acids downstream. Loss of function is an established mechanism of disease for the GJB2 gene. These data were assessed using the ACMG/AMP variant interpretation guidelines. In summary, there is sufficient evidence to classify the p.Gly12Valfs*2 variant as pathogenic for autosomal recessive nonsyndromic hearing loss based on the information above. [ACMG evidence codes used: PVS1; PM3_verystrong] -
Pathogenic, criteria provided, single submitter	research	UNC Molecular Genetics Laboratory, University of North Carolina at Chapel Hill	-	The GJB2 c.35delG (p.G12fs) frameshift variant is reported as the most common pathogenic variant associated with autosomal recessive nonsyndromic hearing loss (PMID: 9285800; 9328482; 9819448; 12176036; 20301449). -

not provided Pathogenic:19

Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 04, 2016	The c.35delG deletion is the most common pathogenic variant associated with hearing loss. Www.ncbi.nlm.nih.gov/books/NBK1272/1 -
Pathogenic, criteria provided, single submitter	clinical testing	Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia	Nov 16, 2015	- -
Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Sep 19, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	May 16, 2023	PM3_very_strong, PS4, PVS1 -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratoire de Génétique Moléculaire, CHU Bordeaux	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Nov 04, 2021	Case control studies suggest this variant is associated with hearing loss; allele frequency of the variant is significantly higher in individuals with hearing loss compared to individuals in the general population (Tsukada et al., 2015; Sloan-Heggen et al., 2016); Frameshift variant predicted to result in protein truncation, as the last 214 amino acids are lost (Stenson et al., 2014); In vitro studies demonstrate that the c.35delG variant results in loss of connexin 26 function (D'Andrea et al., 2002); Classified as pathogenic by the ClinGen Hearing Loss Variant Curation Expert Panel (SCV000840537.3; Oza et al., 2018); This variant is associated with the following publications: (PMID: 20815033, 22975760, 26896187, 29234782, 9819448, 18985073, 25262649, 12833397, 16088916, 21465647, 15070423, 20073550, 19925344, 20739944, 23489192, 27316387, 17666888, 16222667, 27843504, 12189487, 14738110, 25266519, 9285800, 27153395, 26990548, 19274344, 27177047, 25533962, 29501291, 29293505, 29431110, 29016196, 28281779, 17431919, 12169891, 12172392, 30609409, 30730013, 30094485, 29372807, 29542069, 29086887, 30168495, 30390570, 30431684, 31163360, 29907799, 30055715, 31028937, 31370293, 31162818, 30344259, 31564438, 31130284, 31541171, 32279305, 31827275, 31980526, 31160754, 30275481, 10782932, 32747562, 33443819, 14759569, 33096615, 29871260, 33297549, 12068628, 33466560, 33105617, 32067424, 32853555, 32860223, 11355484, 32842620, 31078570, 10713883, 12176036, 26969326, 25999548) -
Pathogenic, no assertion criteria provided	clinical testing	Molecular Genetics laboratory, Necker Hospital	Feb 15, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Apr 01, 2024	GJB2: PM3:Very Strong, PVS1:Strong, PM2, PS3:Supporting -
Pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jan 11, 2023	This variant is expected to result in the loss of a functional protein. This variant is one of the most common variants associated with the recessive form of nonsyndromic hearing loss, DFNB1 (PMID: 20301449), and so therefore the frequency of this variant in the general population is consistent with pathogenicity (Genome Aggregation Database (gnomAD), Cambridge, MA (URL: http://gnomad.broadinstitute.org)). This variant is also referred to as 35delG, and sometimes 30delG, in published literature. In multiple individuals, this variant has been seen with a single recessive pathogenic variant in the same gene. Assessment of experimental evidence suggests this variant results in abnormal protein function. In vitro studies demonstrate this variant results in loss of connexin 26 function (PMID: 12176036). -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genetics and Genomics, Karolinska University Hospital	Sep 03, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics	Nov 24, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Al Jalila Children's Genomics Center, Al Jalila Childrens Speciality Hospital	Dec 17, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital	Aug 15, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 31, 2024	This sequence change creates a premature translational stop signal (p.Gly12Valfs*2) in the GJB2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 215 amino acid(s) of the GJB2 protein. This variant is present in population databases (rs80338939, gnomAD 1.0%), and has an allele count higher than expected for a pathogenic variant. This premature translational stop signal has been observed in individual(s) with autosomal recessive deafness (PMID: 9285800, 9328482, 12239718). It is commonly reported in individuals of European ancestry (PMID: 10751669, 12172392, 12176036, 12239718, 19925344). ClinVar contains an entry for this variant (Variation ID: 17004). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this premature translational stop signal affects GJB2 function (PMID: 12176036). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen	Oct 23, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden	Nov 03, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Nov 07, 2023	The GJB2 c.35delG; p.Gly12ValfsTer2 variant (rs80338939) is the most common pathogenic GJB2 variant found among individuals with European ancestry (Estivill 1998, Gasparini 2000). It has been described in the homozygous and compound heterozygous state in individuals affected with autosomal recessive nonsyndromic hearing loss with severity ranging from mild to profound (Estivill 1998, Gasparini 2000, Putcha 2007). This variant is reported as pathogenic by multiple laboratories in ClinVar (Variation ID: 17004) and is observed in the general population at an overall frequency of 0.6% (1737/280696 alleles, 10 homozygotes) in the Genome Aggregation Database. This variant causes a frameshift by deleting a single nucleotide, and in vitro functional studies demonstrate a loss of connexin 26 function (D’Andrea 2002). Based on available information, this variant is considered pathogenic. References: D’Andrea P et al. Hearing loss: frequency and functional studies of the most common connexin26 alleles. Biochem Biophys Res Commun. 2002 Aug 23;296(3):685-91. PMID: 12176036 Estivill X et al. Connexin-26 mutations in sporadic and inherited sensorineural deafness. Lancet. 1998 Feb 7;351(9100):394-8. PMID: 9482292 Gasparini P et al. High carrier frequency of the 35delG deafness mutation in European populations. Genetic Analysis Consortium of GJB2 35delG. Eur J Hum Genet. 2000 Jan;8(1):19-23. PMID: 10713883 Putcha G et al. A multicenter study of the frequency and distribution of GJB2 and GJB6 mutations in a large North American cohort. Genet Med. 2007 Jul;9(7):413-26. PMID: 17666888 -

Hearing impairment Pathogenic:7

Pathogenic, criteria provided, single submitter	clinical testing	Equipe Genetique des Anomalies du Developpement, Université de Bourgogne	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Department of Otolaryngology – Head & Neck Surgery, Cochlear Implant Center	Apr 12, 2021	PVS1_Strong, PS3_Strong -
Likely pathogenic, no assertion criteria provided	research	University of Washington Center for Mendelian Genomics, University of Washington	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Centre for Mendelian Genomics, University Medical Centre Ljubljana	Jan 01, 2017	- -
Pathogenic, no assertion criteria provided	literature only	Yale Center for Mendelian Genomics, Yale University	Jan 29, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Feb 08, 2013	- -
Pathogenic, no assertion criteria provided	research	Center for Statistical Genetics, Columbia University	Nov 22, 2018	- -

Autosomal dominant nonsyndromic hearing loss 3A Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Mar 08, 2016	- -
Likely pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics Laboratory, University Hospital Schleswig-Holstein	Sep 13, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Centre for Mendelian Genomics, University Medical Centre Ljubljana	Jun 11, 2019	This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PVS1,PS1,PM1. This variant was detected in homozygous state. -

Hearing loss, autosomal recessive Pathogenic:2 Other:1

not provided, no classification provided	phenotyping only	GenomeConnect, ClinGen	-	Variant identified in multiple participants. Variant interpreted as Pathogenic and reported on 10-31-2014 by Lab or GTR ID 50489, reported on 03-17-2020 by Lab or GTR ID 21766, and reported on 11/16/2015 by GTR ID 165021. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
Pathogenic, criteria provided, single submitter	clinical testing	Knight Diagnostic Laboratories, Oregon Health and Sciences University	Sep 21, 2016	- -
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;C1865234:Ichthyosis, hystrix-like, with hearing loss;C2673759:Autosomal recessive nonsyndromic hearing loss 1A;C2675750:Autosomal dominant nonsyndromic hearing loss 3A Pathogenic:2

Pathogenic, no assertion criteria provided	research	Division of Human Genetics, Children's Hospital of Philadelphia	Oct 31, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Genomics, Ann and Robert H. Lurie Children's Hospital of Chicago	Dec 10, 2021	GJB2 NM_004004.5 exon 2 p.Gly12Valfs*2 (c.35delG): This variant is reported to be one of the most common pathogenic GJB2 variants; it has been reported in the literature in the homozygous or compound heterozygous state in numerous individuals with autosomal recessive nonsyndromic hearing loss (Carrasquillo 1997 PMID: 9328482; Denoyelle 1997 PMID: 9336442; Zelante 1997, PMID: 9285800; Green 1999 PMID: 10376574; Gasparini 2000 PMID: 10713883; Kenneson 2002 PMID: 12172392; Bouwer 2007 PMID: 18294064). This variant is present in 0.9% (1217/127068) of European alleles in the Genome Aggregation Database, including 4 homozygotes (http://gnomad.broadinstitute.org/variant/13-20763685-AC-A). Please note, disease causing variants may be present in control databases, reflective of the general population, carrier frequency, and/or variable expressivity. This variant is present in ClinVar, with multiple reporting labs classifying this variant as pathogenic (Variation ID:17004). Evolutionary conservation and computational predictive tools for this variant are limited or unavailable. In vitro functional studies predict that this variant will impact the protein and result in loss of connexin 26 function (D'Andrea 2002 PMID: 12176036). However, these studies may not accurately represent in vivo biological function. This variant is a deletion of one nucleotide and creates a premature stop codon 2 amino acids downstream from this location, which results in an absent or abnormal protein. Loss of function variants are commonly reported in association with disease for this gene (Choi 2011 PMID:21298213). In summary, this variant is classified as pathogenic based on the data above. -

Nonsyndromic genetic hearing loss Pathogenic:2

Pathogenic, reviewed by expert panel	curation	ClinGen Hearing Loss Variant Curation Expert Panel	Sep 20, 2018	The c.35delG variant in GJB2 is predicted to cause a premature stop codon in biologically-relevant-exon 2/2 that leads to a truncated or absent protein in a gene in which loss-of-function is an established mechanism (PVS1). This variant has been detected in patients with hearing loss in trans with at least 4 pathogenic or suspected-pathogenic variants (PM3_VS; PMID: 26445815). This variant was found to have a statistically higher prevalence in affected individuals over controls (PS4; PMID: 26969326, 25999548). The filtering allele frequency of the c.35delG variant in the GJB2 gene is 0.9% for European (Non-Finnish) chromosomes in the Genome Aggregation Database (1207/124552 with 95% CI), which is a high enough frequency to be classified as benign based on thresholds defined by the ClinGen Hearing Loss Expert Panel for autosomal recessive hearing loss variants (BA1). The ClinGen Hearing Loss Expert Panel believes that the evidence for the pathogenicity of this variant for hearing loss outweighs the high allele frequency of the variant in population databases. Therefore, the BA1 code will not contribute to the overall classification. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive non-syndromic hearing loss based on the ACMG/AMP criteria applied, as specified by the Hearing Loss Expert Panel: PVS1, PM3_VS, PS4, BA1. -
Pathogenic, criteria provided, single submitter	clinical testing	INGEBI, INGEBI / CONICET	Aug 31, 2020	Based on ACMG/AMP guidelines and Hearing Loss Expert Panel specific criteria: PVS1, PM3_VS, PS4 -

Bilateral sensorineural hearing impairment;C1384666:Hearing impairment Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Apr 12, 2014

- -

Hearing loss Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Clinical Molecular Genetics Laboratory, Johns Hopkins All Children's Hospital

Feb 22, 2017

- -

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 02, 2022

The c.35delG (p.G12Vfs*2) alteration, located in exon 2 (coding exon 1) of the GJB2 gene, consists of a deletion of one nucleotide at position 35, causing a translational frameshift with a predicted alternate stop codon after 2 amino acids. The GJB2 gene has a single coding exon, so while the alteration is truncating, the mRNA is not predicted to undergo nonsense mediated decay (NMD) and a truncated mutant protein could still be expressed. Premature termination codons located either in the last exon or within 50-55 nucleotides upstream of the 3’-most exon-exon junction usually fail to elicit NMD (Maquat, 2004). The exact functional impact of these altered amino acids is unknown at this time; however, this alteration and additional truncating alterations downstream of this alteration have been reported in the literature as disease-causing (Roux, 2004). Based on data from gnomAD, the - allele has an overall frequency of 0.619% (1737/280696) total alleles studied. The highest observed frequency was 0.958% (1217/127068) of European (non-Finnish) alleles. The c.35delG variant is the most common GJB2 pathogenic variant among Caucasians individuals, and has been reported in patients with mild to profound hearing loss of multiple ethnicities (Denoyelle, 1997; Gasparini, 2000; Gualandi, 2002; Roux, 2004; Hilgert, 2009; Mahdieh, 2016; Zytsar, 2018). Additionally, this variant was observed in trans with p.N176D in multiple families with syndromic hearing loss with ectodermal involvement (Youssefian, 2018; Youssefian, 2022). Functional studies show an absence of protein expression and reduced intercellular diffusion of dye in vitro (D'Andrea, 2002). Based on the available evidence, this alteration is classified as pathogenic. -

Deafness, digenic, GJB2/GJB6 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Oct 05, 2012

- -

Bilateral sensorineural hearing impairment Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Oct 01, 2014

- -

GJB2-related disorder Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Aug 03, 2023

The GJB2 c.35delG variant is predicted to result in a frameshift and premature protein termination (p.Gly12Valfs*2). This variant has been reported to be one of the most common causative variants for autosomal recessive nonsyndromic hearing loss and deafness (Wilcox et al. 2000. PubMed ID: 10830906; D'Andrea et al. 2002. PubMed ID: 12176036; Chan et al. 2010. PubMed ID: 20154630; Dzhemileva et al. 2010. PubMed ID: 20739944). This variant is interpreted as pathogenic. -

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

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

-

- -

Deafness Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

DASA

Sep 02, 2021

The c.35delG variant is a deletion of one guanine in a sequence of six guanines in the GJB2 coding sequence leading to premature chain termination at the twelfth amino acid of the Cx26 protein p.(Gly12Valfs*2) - PVS_strong. Well-established in vitro or in vivo functional studies supportive of a damaging effect on the gene or gene product (PMID: 16773579; 12176036) - PS3_supporting. This variant is the most common in Caucasian populations and is described as pathogenic in the specialized literature, being one of the most common variant associated with non-syndromic deafness phenotype (ClinVar ID: 17004, ClinGen: CA127023, OMIM: 121011.0005, PMID: 20301449, 16773579, 34440441) – PS4. The c.35delG was detected in trans with a pathogenic variant (PMID: 21220926, 26096904, 24039984, 14694360, 34440441, 16849369) – PM3_very strong; and co-segregated with deafnes in multiple affected family members (PMID: 16773579, 24039984, 14694360) – PP1. This variant is observed in the general population (rs80338939 - gnomAD 0,006 frequency; ABraOM 0,0098 frequency - http://abraom.ib.usp.br/). In summary, the currently available evidence indicates that the variant is pathogenic. -

Autosomal recessive nonsyndromic hearing loss 104 Pathogenic:1

Pathogenic, criteria provided, single submitter

not provided

Institute of Human Genetics, University Hospital of Duesseldorf

-

- -

Bilateral conductive hearing impairment;C1384666:Hearing impairment Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Jan 13, 2015

- -

GJB2-Related Autosomal Recessive Nonsyndromic Hearing Loss Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Feb 26, 2024

- -

Knuckle pads, deafness AND leukonychia syndrome Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Genomics England Pilot Project, Genomics England

-

- -

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 05, 2021

- -

Rare genetic deafness Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jun 23, 2022

The c.35delG variant in GJB2 is known to be pathogenic with many supporting publications. ACMG/AMP Criteria applied: PVS1, PM3_VeryStrong. -

Ear malformation Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Kariminejad - Najmabadi Pathology & Genetics Center

Jul 10, 2021

- -

Severe sensorineural hearing impairment Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Jan 04, 2016

- -

Computational scores

Source: dbNSFP v4.3

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

Other links and lift over

dbSNP: rs80338939; hg19: chr13-20763685;