rs756484720
Variant summary
Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong
The NM_004004.6(GJB2):c.334_335delAA(p.Lys112GlufsTer2) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,613,518 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).
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
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| GJB2 | ENST00000382848.5 | c.334_335delAA | p.Lys112GlufsTer2 | frameshift_variant | Exon 2 of 2 | 1 | NM_004004.6 | ENSP00000372299.4 | ||
| GJB2 | ENST00000382844.2 | c.334_335delAA | p.Lys112GlufsTer2 | frameshift_variant | Exon 1 of 1 | 6 | ENSP00000372295.1 | |||
| ENSG00000296095 | ENST00000736390.1 | n.232-3668_232-3667delAA | intron_variant | Intron 1 of 3 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152232Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00000799 AC: 2AN: 250258 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000753 AC: 11AN: 1461286Hom.: 0 AF XY: 0.00000963 AC XY: 7AN XY: 726960 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152232Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74376 show subpopulations
ClinVar
Submissions by phenotype
Autosomal recessive nonsyndromic hearing loss 1A Pathogenic:6
Variant summary: GJB2 c.334_335delAA (p.Lys112GlufsX2) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the 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. The variant allele was found at a frequency of 8e-06 in 250258 control chromosomes. c.334_335delAA has been reported in the literature in multiple individuals affected with Autosomal Recessive Non-Syndromic Hearing Loss, and has been shown to segregate with disease in several families. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). Predicted Consequence/Location: 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. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000189051 /PMID: 9529365). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -
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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. -
not provided Pathogenic:3
This sequence change creates a premature translational stop signal (p.Lys112Glufs*2) in the GJB2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 115 amino acid(s) of the GJB2 protein. This variant is present in population databases (rs756484720, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with non-syndromic deafness (PMID: 9529365, 23141775). It has also been observed to segregate with disease in related individuals. This variant is also known as c.333-334delAA. ClinVar contains an entry for this variant (Variation ID: 189051). This variant disrupts a region of the GJB2 protein in which other variant(s) (p.Gln124*) have been determined to be pathogenic (PMID: 9600457). 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. -
Reported in association with hearing loss in additional cases in published literature (PMID: 21465647, 17666888, 26561413); however, patient clinical information limited or not provided; Frameshift variant predicted to result in abnormal protein length as the last 115 amino acids are replaced with 1 different amino acid, and other similar variants have been reported in HGMD; This variant is associated with the following publications: (PMID: 31215297, 26561413, 27177978, 23141775, 9529365, 26990548, 25587757, 22695344, 17666888, 12172394, 29257206, 27941975, 33096615, 31589614, 34599368, 24158611, 15954104, 21465647) -
This 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. (http://gnomad.broadinstitute.org) This variant has been identified in at least one individual with clinical features associated with nonsyndromic hearing loss and deafness. -
Hearing loss Pathogenic:1
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Nonsyndromic genetic hearing loss Pathogenic:1
Based on ACMG/AMP guidelines and Hearing Loss Expert Panel specific criteria: the c.334_335del variant which leads to p.(Lys112Glufs*2) in the GJB2 gene is present in only 1/34582 Latino alleles in Genome Aggregation Database (http://gnomad.broadinstitute.org); meeting the PM2 criteria. The c.334_335del variant is predicted to cause a premature stop codon in the only exon of GJB2 that leads to a truncated or absent protein in a gene in which loss-of-function is an established mechanism (PVS1). This variant was detected in trans with 2 different pathogenic or suspected pathogenic variants in at least 4 hearing loss patients (PMID: 9529365, 21465647, 22695344, 23141775) applying to PM3_VeryStrong. Two familial cases with two affected siblings in each one showed segregation of the genotypes: c.[334_335del];[35delG] and c.[334_335del];[638T>A] in the affected siblings respectively applying to PP1_Moderate rule (PMID: 9529365, 23141775) In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive non-syndromic hearing loss: PM2, PVS1, PM3_VeryStrong, PP1_Moderate. -
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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Rare genetic deafness Pathogenic:1
The p.Lys112fs variant in GJB2 has been reported in eight individuals with hearing loss (Kelley 1998, Wu 2002, Putcha 2007, Nishio 2015). One of these individuals and their sibling were compound heterozygous for this variant and a second pathogenic GJB2 variant (Kelley 1998). The p.Lys112fs variant has also been identified in 0.002% (1/34582) of Latino chromosomes by gnomAD (http://gnomad.broadinstitute.org). This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 112 and leads to a premature termination codon 2 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Loss of function of the GJB2 gene is an established disease mechanism in autosomal recessive hearing loss. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive hearing loss. ACMG/AMP criteria applied: PVS1, PM2, PM3, PP1. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at