rs201895089
Variant summary
Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1PM2PP5
The NM_004004.6(GJB2):c.-22-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000206 in 1,455,756 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_004004.6 splice_acceptor, intron
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 11 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| GJB2 | NM_004004.6 | c.-22-2A>G | splice_acceptor_variant, intron_variant | Intron 1 of 1 | ENST00000382848.5 | NP_003995.2 | ||
| GJB2 | XM_011535049.3 | c.-22-2A>G | splice_acceptor_variant, intron_variant | Intron 1 of 1 | XP_011533351.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| GJB2 | ENST00000382848.5 | c.-22-2A>G | splice_acceptor_variant, intron_variant | Intron 1 of 1 | 1 | NM_004004.6 | ENSP00000372299.4 | |||
| GJB2 | ENST00000382844.2 | c.-24A>G | 5_prime_UTR_variant | Exon 1 of 1 | 6 | ENSP00000372295.1 | ||||
| ENSG00000296095 | ENST00000736390.1 | n.232-4025A>G | intron_variant | Intron 1 of 3 |
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD4 exome AF: 0.00000206 AC: 3AN: 1455756Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1AN XY: 724646 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
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:1
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not specified Uncertain:1
Variant summary: GJB2 c.-22-2A>G is located in a canonical splice-site, upstream from the coding region of the gene, and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing and loss of GJB2 function. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.9e-06 in 1601428 control chromosomes (gnomAD v4.1). To our knowledge, no occurrence of c.-22-2A>G in individuals affected with Non-Syndromic Hearing Loss and no experimental evidence demonstrating its impact on protein function have been reported. However, a different variant affecting the same nucleotide, c.-22-2A>C, has been reported in affected individuals, and a functional study (PMID 24039984) demonstrated that it abolished the canonical splice-site, resulting in the utilization of two upstream cryptic intronic splice-sites, with a lower expression of two slightly longer transcripts (not affecting the coding part); this variant was classified as likely pathogenic for post-lingual, mild-moderate hearing loss by our lab. These data suggest that other variants that are predicted to disrupt the same splice-site might have similar effect. ClinVar contains an entry for this variant (Variation ID: 551912). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
Autosomal recessive nonsyndromic hearing loss 1A Uncertain:1
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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at