rs121918168
Variant summary
Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PP3_StrongPP5_Very_Strong
The NM_000275.3(OCA2):c.1001C>T(p.Ala334Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000991 in 1,613,900 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 12 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
OCA2 | ENST00000354638.8 | c.1001C>T | p.Ala334Val | missense_variant | Exon 9 of 24 | 1 | NM_000275.3 | ENSP00000346659.3 | ||
OCA2 | ENST00000353809.9 | c.1001C>T | p.Ala334Val | missense_variant | Exon 9 of 23 | 1 | ENSP00000261276.8 |
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 152088Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000797 AC: 2AN: 251086Hom.: 0 AF XY: 0.00000737 AC XY: 1AN XY: 135748
GnomAD4 exome AF: 0.0000103 AC: 15AN: 1461812Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6AN XY: 727196
GnomAD4 genome AF: 0.00000658 AC: 1AN: 152088Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74264
ClinVar
Submissions by phenotype
Tyrosinase-positive oculocutaneous albinism Pathogenic:4
This missense variant replaces a conserved Alanine residue with a Valine. This change is predicted damaging by the vast majority of prediction algorithms. This variant is very rare with no homozygous in gnomAD (AF: 0.00000797), was submited in ClinVar by multiple submitters without conflicting interpretation (VCV000000958.3), and is mentioned in at least two publications (PMID: 29345414‚ PMID: 10649493). We identified this variant in a heterozygous state in one patient with Tyrosinase-positive oculocutaneous albinism in the Democratic Republic of Congo (DRC). This patient was heterozygous for the classic 2.7 deletion in the OCA2 gene. Segregation analysis was not performed to unequivocally establish co-segregation with the 2.7 deletion. This variant was classified as pathogenic according to the ACMG guidelines. -
Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic (ClinVar ID: VCV000000958, PMID:10649493). In silico tool predictions suggest damaging effect of the variant on gene or gene product(REVEL: 0.742>=0.6). A missense variant is a common mechanism. The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.0000080). Therefore, this variant is classified as likely pathogenic according to the recommendation of ACMG/AMP guideline. -
PM2_Supporting+PP3+PM3_VeryStrong+PP4 -
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not provided Pathogenic:1Uncertain:1
This sequence change replaces alanine with valine at codon 334 of the OCA2 protein (p.Ala334Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with ocular albinism (PMID: 10649493, 29345414). In at least one individual the data is consistent with the variant being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 958). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt OCA2 protein function. For these reasons, this variant has been classified as Pathogenic. -
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SKIN/HAIR/EYE PIGMENTATION 1, BLUE/NONBLUE EYES Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at