rs111033211
Variant summary
Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PS4PP1_StrongPM3
This summary comes from the ClinGen Evidence Repository: The filtering allele frequency (the lower threshold of the 95% CI of 143/1558, including 8 homozygous observations) of the c.109G>A (p.Val37Ile) variant in the GJB2 gene is 7.9% for East Asian genomes in gnomAD.This is a high enough frequency that, in the absence of conflicting data, might warrant a benign classification based on the thresholds defined by the ClinGen Hearing Loss Expert Panel for autosomal recessive hearing loss variants (BA1). However, based on the evidence outlined below, the ClinGen Hearing Loss Expert Panel believes that the evidence for the pathogenicity of this variant for nonsyndromic hearing loss outweighs its high allele frequency in population databases. Therefore, the BA1 code will not contribute to the overall classification. The homozygous genotype and compound heterozygous genotype with another variant in GJB2 have shown to be statistically enriched in patients with nonsyndromic sensorineural hearing loss compared to individuals representative of the general population in gnomAD and/or those who underwent carrier screening at Counsyl. (PS4; PMID:31160754). This study also reported the variant in 139 homozygous affected probands, 17 affected probands with the p.Met34Thr variant in trans, 131 affected probands with a variant asserted to be P/LP in ClinVar, and 78 affected probands with a premature GJB2 termination codon in trans. However, because the variant is also very frequent in the general population, this criteria has been applied at the strength of Moderate. (PM3; PMID:31160754). The p.Val37Ile variant in GJB2 has been reported to segregate with hearing loss in at least 21 family members (PP1_Strong; PMID:31160754). Although homozygous or compound heterozygous observations have been identified in individuals with normal hearing, it has been suggested that individuals with the p.Val37Ile variant lose hearing at ~1dB/year, suggesting an age-related penetrance (PMID:27308859). Furthermore, in dye transfer and electrical coupling assays, both functional studies have shown that the variant impacts protein function (PMID:26088551, 12505163, 16300957) and knock-in mouse model demonstrated that the p.Val37Ile variant leads to the phenotype. However, because the codon for p.Val37 in mouse (GTG) was different from that in human (GTT), c.109G>A in mouse would translate into p.Val37Met, and the dye transfer and coupling assays have limited validation and correlation with pathogenicity, neither was not counted as functional evidence. (PMID:27623246). Of note, the severity of hearing loss is known to be mild on average and there have been multiple accounts of incomplete penetrance of the variant in families/individuals with p.Val37Ile in a biallelic genotype. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive nonsyndromic genetic hearing loss based on the ACMG/AMP criteria applied, as specified by the Hearing Loss Expert Panel: PS4, PP1_Strong, PM3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA172210/MONDO:0019497/005
Frequency
Consequence
NM_004004.6 missense
Scores
Clinical Significance
Conservation
Publications
- Bart-Pumphrey syndromeInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
- ichthyosis, hystrix-like, with hearing lossInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp
- keratoderma hereditarium mutilansInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, G2P
- palmoplantar keratoderma-deafness syndromeInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
- autosomal recessive nonsyndromic hearing loss 1AInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, G2P, PanelApp Australia
- hearing loss, autosomal recessiveInheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
- autosomal dominant keratitis-ichthyosis-hearing loss syndromeInheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics
- autosomal dominant nonsyndromic hearing loss 3AInheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
- autosomal dominant nonsyndromic hearing lossInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- KID syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 10 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_004004.6. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| GJB2 | NM_004004.6 | MANE Select | c.109G>A | p.Val37Ile | missense | Exon 2 of 2 | NP_003995.2 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| GJB2 | ENST00000382848.5 | TSL:1 MANE Select | c.109G>A | p.Val37Ile | missense | Exon 2 of 2 | ENSP00000372299.4 | ||
| GJB2 | ENST00000382844.2 | TSL:6 | c.109G>A | p.Val37Ile | missense | Exon 1 of 1 | ENSP00000372295.1 | ||
| GJB2 | ENST00000906230.1 | c.109G>A | p.Val37Ile | missense | Exon 2 of 2 | ENSP00000576289.1 |
Frequencies
GnomAD3 genomes AF: 0.00400 AC: 609AN: 152178Hom.: 18 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00772 AC: 1936AN: 250766 AF XY: 0.00681 show subpopulations
GnomAD4 exome AF: 0.00237 AC: 3462AN: 1461390Hom.: 83 Cov.: 33 AF XY: 0.00222 AC XY: 1616AN XY: 726914 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00400 AC: 609AN: 152296Hom.: 18 Cov.: 33 AF XY: 0.00435 AC XY: 324AN XY: 74470 show subpopulations
Age Distribution
ClinVar
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at