chr13-20189070-G-GCGTT
Variant summary
Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong
The NM_004004.6(GJB2):c.508_511dupAACG(p.Ala171GlufsTer40) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000136 in 1,613,942 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. A171A) has been classified as Likely benign.
Frequency
Consequence
NM_004004.6 frameshift
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 16 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| GJB2 | NM_004004.6 | c.508_511dupAACG | p.Ala171GlufsTer40 | frameshift_variant | Exon 2 of 2 | ENST00000382848.5 | NP_003995.2 | |
| GJB2 | XM_011535049.3 | c.508_511dupAACG | p.Ala171GlufsTer40 | frameshift_variant | Exon 2 of 2 | XP_011533351.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| GJB2 | ENST00000382848.5 | c.508_511dupAACG | p.Ala171GlufsTer40 | frameshift_variant | Exon 2 of 2 | 1 | NM_004004.6 | ENSP00000372299.4 | ||
| GJB2 | ENST00000382844.2 | c.508_511dupAACG | p.Ala171GlufsTer40 | frameshift_variant | Exon 1 of 1 | 6 | ENSP00000372295.1 | |||
| ENSG00000296095 | ENST00000736390.1 | n.232-3494_232-3491dupAACG | intron_variant | Intron 1 of 3 |
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152180Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000199 AC: 5AN: 251100 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.0000123 AC: 18AN: 1461762Hom.: 0 Cov.: 33 AF XY: 0.00000963 AC XY: 7AN XY: 727168 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152180Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74368 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Autosomal recessive nonsyndromic hearing loss 1A Pathogenic:8
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This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
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Variant summary: The GJB2 c.508_511dupAACG (p.Ala171Glufs) 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. One truncation downstream of this position has been classified as pathogenic by our laboratory (c.647_650delGATA/ p.Arg216fs). One in silico tool predicts a damaging outcome for this variant. The variant of interest has been found in a large, broad control population, ExAC in 2/121034 control chromosomes at a frequency of 0.0000165, which does not exceed the estimated maximal expected allele frequency of a pathogenic GJB2 variant (0.0003376). This variant has been reported in multiple studies, in Chinese and Koreean populations with NSHL in the compound heterozygous and homozygous state (Zhu_2015, Kim_2015, Jiang_2014). In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as likely pathogenic/pathogenic. Taken together, this variant is classified as pathogenic. -
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not provided Pathogenic:3
This sequence change creates a premature translational stop signal (p.Ala171Glufs*40) in the GJB2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 56 amino acid(s) of the GJB2 protein. This variant is present in population databases (rs773528125, gnomAD 0.03%). This premature translational stop signal has been observed in individual(s) with autosomal recessive deafness (PMID: 12172394, 25891447). This variant is also known as 511-512insAACG. ClinVar contains an entry for this variant (Variation ID: 189070). This variant disrupts a region of the GJB2 protein in which other variant(s) (p.Cys211Leufs*5) have been determined to be pathogenic (PMID: 9529365, 12910486, 20863150). 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. -
Frameshift variant predicted to result in protein truncation, as the last 56 amino acids are lost and replaced with 39 incorrect amino acids (HGMD); This variant is associated with the following publications: (PMID: 24737404, 12172394, 16712961, 25587757, 26004784, 27247933, 27792752, 26783197, 17444514, 25891447, 24256046, 23638949, 22335977, 22695344, 28717060, 29926981, 31160754, 29871260) -
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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
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GJB2-related disorder Pathogenic:1
The GJB2 c.508_511dupAACG variant is predicted to result in a frameshift and premature protein termination (p.Ala171Glufs*40). This variant has been reported in multiple individuals with non‑syndromic hearing loss (see for example, Table 1, Wu et al. 2002. PubMed ID: 12172394; Table 4, Jiang et al. 2014. PubMed ID: 24737404; Table S3, Yuan et al. 2019. PubMed ID: 31541171). This variant is reported in 0.030% of alleles in individuals of East Asian descent in gnomAD (http://gnomad.broadinstitute.org/variant/13-20763209-G-GCGTT). Frameshift variants in GJB2 are expected to be pathogenic. This variant is interpreted as pathogenic. -
Ear malformation Pathogenic:1
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Rare genetic deafness Pathogenic:1
The p.Ala171fs variant in GJB2 has been reported in several individuals with nonsyndromic hearing loss in the compound heterozygous and homozygous state (Wu 2002 PubMed: 12172394, Liu 2020 PubMed: 32645618, Yuan 2020 PubMed: 31541171). It has also been identified in 4/5196 (0.07%) of East Asian chromosomes by gnomAD (httpe://gnomad.broadinstitute.org). However, this frequncy is low enough to be consistent with a recessive allele frequency. This variant is predicted cause a frameshift, which alters the protein's amino acid sequence beginning at position171 and leads to a premature termination codon 40 amino acids downstream. Several frameshift variant downstream of this variant in GJB2 have been reported as disease causing. Loss of function of the GJB2 gene is an established disease mechanism in autosomal recessive nonsyndromic hearing loss. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive nonsyndromic hearing loss. ACMG/AMP Criteria applied: PVS1, PM3_S, PM2_P. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at