chr15-28081703-GC-G

Variant names:

• chr15-28081703-GC-G
• rs1555391997
• NM_000275.3:c.171delG

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000275.3(OCA2):​c.171delG​(p.Gln58ArgfsTer44) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. G57G) has been classified as Uncertain significance. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: OCA2 NM_000275.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.227
• 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: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics, G2P, ClinGen

ACMG classification

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

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 15-28081703-GC-G is Pathogenic according to our data. Variant chr15-28081703-GC-G is described in ClinVar as Pathogenic. ClinVar VariationId is 436098.Status of the report is criteria_provided_single_submitter, 1 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	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	OCA2	NM_000275.3	MANE Select	c.171delG	p.Gln58ArgfsTer44	frameshift	Exon 2 of 24	NP_000266.2
	OCA2	NM_001300984.2		c.171delG	p.Gln58ArgfsTer44	frameshift	Exon 2 of 23	NP_001287913.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	OCA2	ENST00000354638.8	TSL:1 MANE Select	c.171delG	p.Gln58ArgfsTer44	frameshift	Exon 2 of 24	ENSP00000346659.3
	OCA2	ENST00000353809.9	TSL:1	c.171delG	p.Gln58ArgfsTer44	frameshift	Exon 2 of 23	ENSP00000261276.8
	OCA2	ENST00000910120.1		c.171delG	p.Gln58ArgfsTer44	frameshift	Exon 2 of 26	ENSP00000580179.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Tyrosinase-positive oculocutaneous albinism (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.23
Mutation Taster		=1/199	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

Other links and lift over

dbSNP: rs1555391997; hg19: chr15-28326849;