rs121918171

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM2PP3_Strong

The NM_000275.3(OCA2):​c.1182G>A​(p.Met394Ile) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000274 in 1,461,576 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

OCA2
NM_000275.3 missense, splice_region

Scores

11
5
2
Splicing: ADA: 1.000
2

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:1

Conservation

PhyloP100: 6.96

Publications

6 publications found
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 Gene-Disease associations (from GenCC):
  • oculocutaneous albinism type 2
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics, G2P, ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000275.3
PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
OCA2NM_000275.3 linkc.1182G>A p.Met394Ile missense_variant, splice_region_variant Exon 11 of 24 ENST00000354638.8 NP_000266.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
OCA2ENST00000354638.8 linkc.1182G>A p.Met394Ile missense_variant, splice_region_variant Exon 11 of 24 1 NM_000275.3 ENSP00000346659.3
OCA2ENST00000353809.9 linkc.1110G>A p.Met370Ile missense_variant, splice_region_variant Exon 10 of 23 1 ENSP00000261276.8

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251298
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000163
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461576
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727080
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.000101
AC:
4
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86238
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111758
Other (OTH)
AF:
0.00
AC:
0
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.438
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Tyrosinase-positive oculocutaneous albinism Pathogenic:1Uncertain:1
Dec 06, 2023
3billion
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.001%). Predicted Consequence/Location: Missense variant In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.89 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.78 (>=0.6, sensitivity 0.72 and precision 0.9)]. Same nucleotide change resulting in same amino acid change has been previously reported to be associated with OCA2-related disorder (ClinVar ID: VCV000000965 /PMID: 12713581). However, the evidence of pathogenicity is insufficient at this time. Therefore, this variant is classified as VUS according to the recommendation of ACMG/AMP guideline.

Jan 01, 2005
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.28
D
BayesDel_noAF
Pathogenic
0.43
CADD
Pathogenic
36
DANN
Uncertain
1.0
DEOGEN2
Benign
0.0
.;D
Eigen
Pathogenic
0.93
Eigen_PC
Pathogenic
0.84
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Uncertain
0.11
D
MetaRNN
Pathogenic
0.97
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Benign
0.0
.;M
PhyloP100
7.0
PrimateAI
Uncertain
0.69
T
PROVEAN
Uncertain
-3.5
D;D
REVEL
Pathogenic
0.89
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Vest4
0.95
ClinPred
0.91
D
GERP RS
5.0
Varity_R
0.84
gMVP
0.98
Mutation Taster
=5/95
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
1.0
Splicevardb
1.0
SpliceAI score (max)
0.71
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.61
Position offset: -42
DS_DL_spliceai
0.71
Position offset: 0

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

Publications

Other links and lift over

dbSNP: rs121918171; hg19: chr15-28234747; API