rs111033361

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2_SupportingPM3_StrongPP3PP1

This summary comes from the ClinGen Evidence Repository: The c.227T>C is a missense variant in GJB2 predicted to cause substitution of leucine to proline at amino acid 76. The highest population minor allele frequency in gnomAD v4.1 is 0.0006779% (8/1180042) in the European (non-Finnish) population, which is a low enough frequency to apply PM2_Supporting based on the thresholds defined by the ClinGen Hearing Loss Expert Panel for autosomal recessive hearing loss (PM2_Supporting). The variant has been detected in 4 probands with hearing loss (3.0 PM3 points). For two of those patients, a pathogenic variant was observed in trans (PMID:17666888, 19274344), in a third the variant was observed in a homozygous state (ARUP Laboratories internal data, SCV001158697.1), and in the last patient the variant was observed with another pathogenic variant although with unknown phase (Partners LMM internal data, SCV000061486.5) (PM3_Strong). The variant has been reported to segregate with hearing loss in one affected family member (PP1, PMID:19274344). The REVEL computational prediction tool produced a score of 0.976, which is above the threshold necessary to apply PP3. In summary, this variant meets criteria to be classified as likely pathogenic for autosomal recessive nonsyndromic hearing loss based on the ACMG/AMP criteria applied as specified by the ClinGen Hearing Loss Expert Panel : PM3_Strong, PM2_Supporting, PP1, PP3. (The ClinGen Hearing Loss VCEP Specifications Version 2, 04/17/2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA134953/MONDO:0019497/005

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

GJB2
NM_004004.6 missense

Scores

Clinical Significance

Likely pathogenic reviewed by expert panel P:6U:1

Conservation

PhyloP100: 9.27

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 Likely_pathogenic. Variant got 7 ACMG points.

PM2

For more information check the summary or visit ClinGen Evidence Repository.

PM3

For more information check the summary or visit ClinGen Evidence Repository.

PP1

For more information check the summary or visit ClinGen Evidence Repository.

PP3

For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJB2	NM_004004.6 link	c.227T>C	p.Leu76Pro	missense_variant	Exon 2 of 2	ENST00000382848.5	NP_003995.2	P29033H9U1J4
GJB2	XM_011535049.3 link	c.227T>C	p.Leu76Pro	missense_variant	Exon 2 of 2		XP_011533351.1	P29033H9U1J4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJB2	ENST00000382848.5 link	c.227T>C	p.Leu76Pro	missense_variant	Exon 2 of 2	1	NM_004004.6	ENSP00000372299.4		P29033
GJB2	ENST00000382844.2 link	c.227T>C	p.Leu76Pro	missense_variant	Exon 1 of 1	6		ENSP00000372295.1		P29033

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152222

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

251410

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135900

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000440

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461848

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727224

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000629

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152222

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74364

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:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000324

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:6Uncertain:1

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Nov 03, 2023

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Classified as likely pathogenic by the ClinGen Hearing Loss Expert Panel (ClinVar SCV001428430.1; PMID: 30311386); This variant is associated with the following publications: (PMID: 25388846, 19274344, 30245029, 34599368, 17666888, 22567359, 30311386) -

Jul 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 76 of the GJB2 protein (p.Leu76Pro). This variant is present in population databases (rs111033361, gnomAD 0.004%). This missense change has been observed in individual(s) with non-syndromic deafness (PMID: 19274344). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 44731). 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 GJB2 protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

not specified

Pathogenic:1Uncertain:1

Mar 01, 2008

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 09, 2018

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The GJB2 c.227T>C; p.Leu76Pro variant (rs111033361) has been described in the compound heterozygous state in individuals with hearing loss, ranging from mild to profound (Batissoco 2009, Nogueira 2011, Putcha 2007). It is reported in ClinVar (Variation ID: 44731), and observed in the European (Non-Finnish) population at a low overall frequency of 0.0036% (4/11678 alleles) in the Genome Aggregation Database. The leucine at codon 76 is highly conserved, and computational algorithms (PolyPhen-2, SIFT) predict that this variant is deleterious. Additionally, other variants at positions adjacent to codon 76 (p.Arg75Gln, p.Arg75Trp, p.Trp77Arg) have been described in association with hearing loss and are considered pathogenic (see link to Connexin Deafness database and references therein, Carrasquillo 1997). Based on available information, the p.Leu76Pro variant is considered likely pathogenic. References: Link to Connexin Deafness database: http://davinci.crg.es/deafness/ Batissoco A et al. A novel missense mutation p.L76P in the GJB2 gene causing nonsyndromic recessive deafness in a Brazilian family. Braz J Med Biol Res. 2009 Feb;42(2):168-71. Carrasquillo M et al. Two different connexin 26 mutations in an inbred kindred segregating non-syndromic recessive deafness: implications for genetic studies in isolated populations. Hum Mol Genet. 1997 Nov;6(12):2163-72. Nogueira C et al. Molecular investigation of pediatric portuguese patients with sensorineural hearing loss. Genet Res Int. 2011;2011:587602. 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. -

Autosomal recessive nonsyndromic hearing loss 1A

Pathogenic:1

Dec 03, 2024

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GJB2 c.227T>C (p.Leu76Pro) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 251410 control chromosomes (gnomAD). c.227T>C has been reported in the literature in multiple individuals affected with Autosomal Recessive Non-Syndromic Hearing Loss (e.g. Putcha_2007, Batissoco_2009, Nogueira_2011, Imzcoz_2023). 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. The following publications have been ascertained in the context of this evaluation (PMID: 17666888, 19274344, 22567359, 37811145). ClinVar contains an entry for this variant (Variation ID: 44731). To our knowledge, the variant has not been found in individuals with Autosomal Dominant Non-Syndromic Hearing Loss. Based on the evidence outlined above, the variant was classified as pathogenic. -

Nonsyndromic genetic hearing loss

Pathogenic:1

Apr 23, 2024

ClinGen Hearing Loss Variant Curation Expert Panel

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.227T>C is a missense variant in GJB2 predicted to cause substitution of leucine to proline at amino acid 76. The highest population minor allele frequency in gnomAD v4.1 is 0.0006779% (8/1180042) in the European (non-Finnish) population, which is a low enough frequency to apply PM2_Supporting based on the thresholds defined by the ClinGen Hearing Loss Expert Panel for autosomal recessive hearing loss (PM2_Supporting). The variant has been detected in 4 probands with hearing loss (3.0 PM3 points). For two of those patients, a pathogenic variant was observed in trans (PMID: 17666888, 19274344), in a third the variant was observed in a homozygous state (ARUP Laboratories internal data, SCV001158697.1), and in the last patient the variant was observed with another pathogenic variant although with unknown phase (Partners LMM internal data, SCV000061486.5) (PM3_Strong). The variant has been reported to segregate with hearing loss in one affected family member (PP1, PMID: 19274344). The REVEL computational prediction tool produced a score of 0.976, which is above the threshold necessary to apply PP3. In summary, this variant meets criteria to be classified as likely pathogenic for autosomal recessive nonsyndromic hearing loss based on the ACMG/AMP criteria applied as specified by the ClinGen Hearing Loss Expert Panel : PM3_Strong, PM2_Supporting, PP1, PP3. (The ClinGen Hearing Loss VCEP Specifications Version 2, 04/17/2024) -

Autosomal dominant nonsyndromic hearing loss 3A

Pathogenic:1

Feb 14, 2022

DASA

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.227T>C;p.(Leu76Pro) missense variant has been observed in affected individual(s) and ClinVar contains an entry for this variant (ClinVar ID: 44731; PMID: 19274344; 17666888) - PS4. The variant is present at low allele frequencies population databases (rs111033361 - gnomAD 0.00006569%; ABraOM no frequency - http://abraom.ib.usp.br/) - PM2_supporting. The p.(Leu76Pro) was detected in trans with a pathogenic variant (PMID: 17666888; 19274344) - PM3. The variant co-segregated with disease in multiple affected family members (PMID: 19274344) - PP1. Multiple lines of computational evidence support a deleterious effect on the gene or gene product - PP3. In summary, the currently available evidence indicates that the variant is likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.49

BayesDel_noAF

Pathogenic

0.58

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.94

D;D;D

Eigen

Pathogenic

0.88

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.93

.;.;D

M_CAP

Pathogenic

0.60

MetaRNN

Pathogenic

0.98

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.3

M;M;M

PrimateAI

Pathogenic

0.87

PROVEAN

Pathogenic

-6.9

D;D;.

REVEL

Pathogenic

0.98

Sift

Pathogenic

0.0

D;D;.

Sift4G

Uncertain

0.0020

D;D;.

Polyphen

1.0

D;D;D

Vest4

0.98

MVP

0.92

MPC

0.34

ClinPred

0.97

GERP RS

5.2

Varity_R

0.98

gMVP

0.99

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