15-27755414-C-G

Position:

chr15-27755414-C-G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2PP3_ModeratePP5_Very_Strong

The NM_000275.3(OCA2):c.2491G>C(p.Ala831Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,246 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: 32)

Consequence

OCA2
NM_000275.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2

Conservation

PhyloP100: 3.19

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]

OCA2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.932

PP5

Variant 15-27755414-C-G is Pathogenic according to our data. Variant chr15-27755414-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2736158.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
OCA2	NM_000275.3 linkuse as main transcript	c.2491G>C	p.Ala831Pro	missense_variant	24/24	ENST00000354638.8	NP_000266.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
OCA2	ENST00000354638.8 linkuse as main transcript	c.2491G>C	p.Ala831Pro	missense_variant	24/24	1	NM_000275.3	ENSP00000346659	P1	Q04671-1
OCA2	ENST00000353809.9 linkuse as main transcript	c.2419G>C	p.Ala807Pro	missense_variant	23/23	1		ENSP00000261276		Q04671-2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152128

Hom.:

Cov.:

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:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251106

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135766

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152246

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74432

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Oculocutaneous albinism

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

May 01, 2024

Variant summary: OCA2 c.2491G>C (p.Ala831Pro) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251106 control chromosomes (gnomAD v2.1). c.2491G>C has been reported in the literature in at least 4 compound heterozygous individuals affected with Oculocutaneous Albinism, who carried a second (likely) pathogenic variant (Wei_2011, Wei_2022). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 21458243, 34838614). ClinVar contains an entry for this variant (Variation ID: 2736158). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 30, 2023

This sequence change replaces alanine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 831 of the OCA2 protein (p.Ala831Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with oculocutaneous albinism (PMID: 21458243, 34838614). 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 not expected to disrupt OCA2 protein function with a negative predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.62

BayesDel_addAF

Pathogenic

0.38

BayesDel_noAF

Pathogenic

0.30

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.70

.;D

Eigen

Uncertain

0.24

Eigen_PC

Benign

0.12

FATHMM_MKL

Benign

0.67

LIST_S2

Uncertain

0.89

D;D

M_CAP

Benign

0.043

MetaRNN

Pathogenic

0.93

D;D

MetaSVM

Uncertain

0.69

MutationAssessor

Benign

2.0

.;M

MutationTaster

Benign

1.0

N;N

PrimateAI

Benign

0.38

PROVEAN

Uncertain

-3.3

D;D

REVEL

Pathogenic

0.77

Sift

Uncertain

0.010

D;D

Sift4G

Uncertain

0.016

D;D

Polyphen

0.98

D;P

Vest4

0.88

MVP

0.98

MPC

0.51

ClinPred

0.97

GERP RS

4.9

Varity_R

0.78

gMVP

0.92

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over