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

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00011 ( 0 hom. )

Consequence

OCA2
NM_000275.3 missense

Scores

10
7
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6U:1

Conservation

PhyloP100: 6.34
Variant links:
Genes affected
OCA2 (HGNC:8101): (OCA2 melanosomal transmembrane protein) This gene encodes the human homolog of the mouse p (pink-eyed dilution) gene. The encoded protein is believed to be an integral membrane protein involved in small molecule transport, specifically tyrosine, which is a precursor to melanin synthesis. It is involved in mammalian pigmentation, where it may control skin color variation and act as a determinant of brown or blue eye color. Mutations in this gene result in type 2 oculocutaneous albinism. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2014]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PM1
In a transmembrane_region Helical (size 16) in uniprot entity P_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_000275.3
PP3
MetaRNN computational evidence supports a deleterious effect, 0.838
PP5
Variant 15-27851390-C-T is Pathogenic according to our data. Variant chr15-27851390-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 429697.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-27851390-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
OCA2NM_000275.3 linkc.2330G>A p.Cys777Tyr missense_variant Exon 22 of 24 ENST00000354638.8 NP_000266.2 Q04671-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
OCA2ENST00000354638.8 linkc.2330G>A p.Cys777Tyr missense_variant Exon 22 of 24 1 NM_000275.3 ENSP00000346659.3 Q04671-1
OCA2ENST00000353809.9 linkc.2258G>A p.Cys753Tyr missense_variant Exon 21 of 23 1 ENSP00000261276.8 Q04671-2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152224
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000321
AC:
8
AN:
249000
Hom.:
0
AF XY:
0.0000371
AC XY:
5
AN XY:
134942
show subpopulations
Gnomad AFR exome
AF:
0.0000625
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000109
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000444
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000106
AC:
155
AN:
1461488
Hom.:
0
Cov.:
31
AF XY:
0.000114
AC XY:
83
AN XY:
727016
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000504
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.000138
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152224
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74364
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000564
Hom.:
0
Bravo
AF:
0.0000113
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.0000412
AC:
5
EpiCase
AF:
0.000164
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:6Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Tyrosinase-positive oculocutaneous albinism Pathogenic:2
-
Laboratoire de Génétique Moléculaire, CHU Bordeaux
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

May 06, 2021
Victorian Clinical Genetics Services, Murdoch Childrens Research Institute
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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
Jan 13, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. -

Feb 21, 2023
GeneDx
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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
Aug 14, 2023
Baylor Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Tyrosinase-positive oculocutaneous albinism;C1856895:SKIN/HAIR/EYE PIGMENTATION 1, BLUE/NONBLUE EYES Pathogenic:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

OCA2-related disorder Uncertain:1
May 10, 2024
PreventionGenetics, part of Exact Sciences
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.22
D
BayesDel_noAF
Pathogenic
0.31
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.81
.;D
Eigen
Uncertain
0.48
Eigen_PC
Uncertain
0.48
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.86
D;D
M_CAP
Benign
0.081
D
MetaRNN
Pathogenic
0.84
D;D
MetaSVM
Uncertain
0.53
D
MutationAssessor
Pathogenic
3.1
.;M
PrimateAI
Pathogenic
0.85
D
PROVEAN
Pathogenic
-9.7
D;D
REVEL
Pathogenic
0.77
Sift
Uncertain
0.0010
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
0.69
P;B
Vest4
0.91
MutPred
0.56
.;Loss of catalytic residue at L778 (P = 0.0393);
MVP
0.94
MPC
0.27
ClinPred
0.99
D
GERP RS
4.9
Varity_R
0.89
gMVP
0.96

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs776814755; hg19: chr15-28096536; API