rs1555422232

Variant names:

• chr15-27871923-C-T
• rs1555422232
• NM_000275.3:c.2080-1G>A

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_000275.3(OCA2):​c.2080-1G>A variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. 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 Pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: OCA2 NM_000275.3 splice_acceptor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.58
• Publications: 1 publications found

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: G2P, Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics, ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.023837902 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.6, offset of 1, new splice context is: cacacatcctttcttctaAGcat. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 15-27871923-C-T is Pathogenic according to our data. Variant chr15-27871923-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 436092.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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	OCA2	NM_000275.3	MANE Select	c.2080-1G>A		splice_acceptor intron	N/A	NP_000266.2	Q04671-1
	OCA2	NM_001300984.2		c.2008-1G>A		splice_acceptor intron	N/A	NP_001287913.1	Q04671-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	OCA2	ENST00000354638.8	TSL:1 MANE Select	c.2080-1G>A		splice_acceptor intron	N/A	ENSP00000346659.3	Q04671-1
	OCA2	ENST00000353809.9	TSL:1	c.2008-1G>A		splice_acceptor intron	N/A	ENSP00000261276.8	Q04671-2
	OCA2	ENST00000910120.1		c.2284-1G>A		splice_acceptor intron	N/A	ENSP00000580179.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
1	-	-	not provided (1)
1	-	-	Tyrosinase-positive oculocutaneous albinism (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.17
CADD	Pathogenic	26
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		6.6
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.90		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.90		Position offset: -1

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs1555422232;

hg19: chr15-28117069;