rs776814755
Variant summary
Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1PP3PP5_Very_Strong
The NM_000275.3(OCA2):c.2330G>A(p.Cys777Tyr) variant causes a missense change. The variant allele was found at a frequency of 0.0000967 in 1,613,712 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000275.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 11 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
OCA2 | ENST00000354638.8 | c.2330G>A | p.Cys777Tyr | missense_variant | Exon 22 of 24 | 1 | NM_000275.3 | ENSP00000346659.3 | ||
OCA2 | ENST00000353809.9 | c.2258G>A | p.Cys753Tyr | missense_variant | Exon 21 of 23 | 1 | ENSP00000261276.8 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152224Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000321 AC: 8AN: 249000Hom.: 0 AF XY: 0.0000371 AC XY: 5AN XY: 134942
GnomAD4 exome AF: 0.000106 AC: 155AN: 1461488Hom.: 0 Cov.: 31 AF XY: 0.000114 AC XY: 83AN XY: 727016
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152224Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74364
ClinVar
Submissions by phenotype
Tyrosinase-positive oculocutaneous albinism Pathogenic:2
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Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Likely pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with brown oculocutaneous albinism and oculocutaneous, type II albinism (MIM#203200). (I) 0106 - This gene is associated with autosomal recessive disease. A single variant has been reported in two families with dominant oculocutaneous albinism (PMID: 32741191). (I) 0115 - Variants in this gene causing oculocutaneous albinism are known to have variable expressivity (PMID: 24518832). (I) 0200 - Variant is predicted to result in a missense amino acid change from cysteine to tyrosine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2) <0.01 for a condition (8 heterozygotes, 0 homozygotes). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated transmembrane helix within the permease P domain (NCBI). (I) 0704 - Another missense variant comparable to the one identified in this case has limited previous evidence for pathogenicity. An alternative change p.(Cys777Arg) has been reported in a heterozygous patient with albinism (PMID: 20861488). (SP) 0802 - This variant has moderate previous evidence of pathogenicity in unrelated individuals. This variant has been reported twice as likely pathogenic (ClinVar), and has been observed in a heterozygous patient with albinism (PMID: 28976636). (SP) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1206 - This variant has been shown to be paternally inherited (LABID). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
not provided Pathogenic:2
This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 777 of the OCA2 protein (p.Cys777Tyr). This variant is present in population databases (rs776814755, gnomAD 0.01%). This missense change has been observed in individuals with clinical features of oculocutaneous albinism (PMID: 28976636; internal data). ClinVar contains an entry for this variant (Variation ID: 429697). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt OCA2 protein function with a positive predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -
Observed with a second OCA2 variant in an individual with clinical oculocutaneous albinism, but it is not known whether the variants occurred on the same (in cis) or on different (in trans) chromosomes (Ma L et al., 2021); Identified in two families with cutaneous malignant melanoma, including one individual who harbored a second OCA2 missense variant, but additional clinical information was not provided (Goldstein et al., 2017); Identified as a single heterozygous variant in a proband with features of oculocutaneous albinism (Marti et al., 2018); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 32966289, 29036293, 34707637, 28976636) -
SKIN/HAIR/EYE PIGMENTATION 1, BLUE/NONBLUE EYES Pathogenic:1
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Tyrosinase-positive oculocutaneous albinism;C1856895:SKIN/HAIR/EYE PIGMENTATION 1, BLUE/NONBLUE EYES Pathogenic:1
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OCA2-related disorder Uncertain:1
The OCA2 c.2330G>A variant is predicted to result in the amino acid substitution p.Cys777Tyr. This variant has been reported in an individual with oculocutaneous albinism, but a second variant in the OCA2 gene was not detected (Marti et al. 2017. PubMed ID: 28976636). This variant has also been reported along with a variant of uncertain significance in OCA2 in an individual with oculocutaneous albinism (Ma et al. 2021. PubMed ID: 34707637). Additionally this variant has been reported in the heterozygous state in individuals who developed cutaneous malignant melanoma (Goldstein et al. 2017. PubMed ID: 29036293). This variant is documented in 0.011% of alleles in individuals of East Asian descent in gnomAD. Although we suspect that this variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at