rs121918168

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A334T) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

OCA2
NM_000275.3 missense

Scores

8
7
3

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 8.43

Publications

9 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: Pathogenic. The variant received 18 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 6 uncertain in NM_000275.3
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr15-28014820-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 522150.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.982
PP5
Variant 15-28014819-G-A is Pathogenic according to our data. Variant chr15-28014819-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 958.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000275.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
OCA2
NM_000275.3
MANE Select
c.1001C>Tp.Ala334Val
missense
Exon 9 of 24NP_000266.2
OCA2
NM_001300984.2
c.1001C>Tp.Ala334Val
missense
Exon 9 of 23NP_001287913.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
OCA2
ENST00000354638.8
TSL:1 MANE Select
c.1001C>Tp.Ala334Val
missense
Exon 9 of 24ENSP00000346659.3
OCA2
ENST00000353809.9
TSL:1
c.1001C>Tp.Ala334Val
missense
Exon 9 of 23ENSP00000261276.8

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152088
Hom.:
0
Cov.:
32
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
GnomAD2 exomes
AF:
0.00000797
AC:
2
AN:
251086
AF XY:
0.00000737
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1461812
Hom.:
0
Cov.:
32
AF XY:
0.00000825
AC XY:
6
AN XY:
727196
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53354
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000117
AC:
13
AN:
1112004
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
2
3
5
6
8
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
AF:
0.00000658
AC:
1
AN:
152088
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74264
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41402
American (AMR)
AF:
0.00
AC:
0
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Tyrosinase-positive oculocutaneous albinism Pathogenic:4
Aug 06, 2022
Centre for Human Genetics, University of Kinshasa
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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.

Aug 01, 2024
3billion
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v4.0.0 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: 0.74 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.35 (>=0.6, sensitivity 0.72 and precision 0.9)]. The same nucleotide change resulting in the same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000000958 /PMID: 10649493 /3billion dataset). A different missense change at the same codon (p.Ala334Thr) has been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000522150). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline.

Jan 01, 2000
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

Juno Genomics, Hangzhou Juno Genomics, Inc
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Absent from controls (or at extremely low frequency if recessive) in Genome Aggregation Database, Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium.;Multiple lines of computational evidence support a deleterious effect on the gene or gene product (conservation, evolutionary, splicing impact, etc).;For recessive disorders, detected in trans with a pathogenic variant.;Patient's phenotype or family history is highly specific for a disease with a single genetic etiology.

not provided Pathogenic:2
Sep 24, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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.

Feb 09, 2024
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

SKIN/HAIR/EYE PIGMENTATION 1, BLUE/NONBLUE EYES Pathogenic:1
Mar 04, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.82
BayesDel_addAF
Pathogenic
0.40
D
BayesDel_noAF
Pathogenic
0.44
CADD
Uncertain
25
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.71
D
Eigen
Uncertain
0.54
Eigen_PC
Uncertain
0.43
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.84
T
M_CAP
Benign
0.080
D
MetaRNN
Pathogenic
0.98
D
MetaSVM
Pathogenic
0.83
D
MutationAssessor
Pathogenic
3.0
M
PhyloP100
8.4
PrimateAI
Uncertain
0.58
T
PROVEAN
Uncertain
-2.9
D
REVEL
Pathogenic
0.74
Sift
Benign
0.033
D
Sift4G
Uncertain
0.0080
D
Polyphen
1.0
D
Vest4
0.89
MutPred
0.81
Gain of catalytic residue at A334 (P = 0.1549)
MVP
0.98
MPC
0.48
ClinPred
0.95
D
GERP RS
5.5
Varity_R
0.50
gMVP
0.85
Mutation Taster
=1/99
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs121918168; hg19: chr15-28259965; COSMIC: COSV62348141; COSMIC: COSV62348141; API