Genetic Variant OCA2:c.*1T>C (chr15-27755387-A-G) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BP4_Strong

The NM_000275.3(OCA2):c.*1T>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000147 in 1,601,594 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00074 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000085 ( 0 hom. )

Consequence

OCA2
NM_000275.3 3_prime_UTR

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 0.0600

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:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.86).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
OCA2	NM_000275.3 link	c.*1T>C		3_prime_UTR_variant	Exon 24 of 24	ENST00000354638.8	NP_000266.2	Q04671-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
OCA2	ENST00000354638 link	c.*1T>C		3_prime_UTR_variant	Exon 24 of 24	1	NM_000275.3	ENSP00000346659.3		Q04671-1
OCA2	ENST00000353809 link	c.*1T>C		3_prime_UTR_variant	Exon 23 of 23	1		ENSP00000261276.8		Q04671-2

Frequencies

GnomAD3 genomes

AF:

0.000743

AC:

113

AN:

152188

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00261

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000262

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:

0.00

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000167

AC:

AN:

251274

Hom.:

AF XY:

0.000118

AC XY:

AN XY:

135840

show subpopulations

Gnomad AFR exome

AF:

0.00246

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000849

AC:

123

AN:

1449288

Hom.:

Cov.:

AF XY:

0.0000554

AC XY:

AN XY:

721708

show subpopulations

Gnomad4 AFR exome

AF:

0.00343

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000273

Gnomad4 OTH exome

AF:

0.0000667

GnomAD4 genome

AF:

0.000742

AC:

113

AN:

152306

Hom.:

Cov.:

AF XY:

0.000725

AC XY:

AN XY:

74466

show subpopulations

Gnomad4 AFR

AF:

0.00260

Gnomad4 AMR

AF:

0.000261

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000787

Hom.:

Bravo

AF:

0.000914

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Tyrosinase-positive oculocutaneous albinism

Uncertain:2

Nov 07, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not provided

Uncertain:2

Feb 06, 2017

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Breakthrough Genomics, Breakthrough Genomics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

not specified

Uncertain:1

Nov 12, 2024

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: OCA2 c.*1T>C is located in the untranslated mRNA region downstream of the termination codon. The variant allele was found at a frequency of 0.00017 in 251274 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in OCA2 causing Oculocutaneous Albinism (0.00017 vs 0.0043), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.*1T>C in individuals affected with Oculocutaneous Albinism and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 499953). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.86

CADD

Benign

0.12

DANN

Benign

0.76

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