NM_001205254.2:c.23delG

Variant names:

• chr5-69504266-AG-A
• rs1580547770
• NM_001205254.2:c.23delG

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_001205254.2(OCLN):​c.23delG​(p.Ser8IlefsTer57) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: OCLN NM_001205254.2 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.80

Genes affected

OCLN (HGNC:8104): (occludin) This gene encodes an integral membrane protein that is required for cytokine-induced regulation of the tight junction paracellular permeability barrier. Mutations in this gene are thought to be a cause of band-like calcification with simplified gyration and polymicrogyria (BLC-PMG), an autosomal recessive neurologic disorder that is also known as pseudo-TORCH syndrome. Alternative splicing results in multiple transcript variants. A related pseudogene is present 1.5 Mb downstream on the q arm of chromosome 5. [provided by RefSeq, Apr 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.985 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-69504266-AG-A is Pathogenic according to our data. Variant chr5-69504266-AG-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 817656.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
OCLN	NM_001205254.2	c.23delG	p.Ser8IlefsTer57	frameshift_variant	Exon 2 of 9	ENST00000396442.7	NP_001192183.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
OCLN	ENST00000396442.7	c.23delG	p.Ser8IlefsTer57	frameshift_variant	Exon 2 of 9	1	NM_001205254.2	ENSP00000379719.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Mar 07, 2018

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A variant that is likely pathogenic has been identified in the OCLN gene. The c.23delG variant causes a frameshift starting with codon Serine 8, changes this amino acid to an Isoleucine residue and creates a premature Stop codon at position 57 of the new reading frame, denoted p.Ser8IlefsX57. This likely pathogenic variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The c.23delG variant is not observed in large population cohorts (Lek et al., 2016). Therefore, this variant is likely pathogenic; however, the possibility that it is benign cannot be excluded. -

Computational scores

Source: dbNSFP v4.3

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

Other links and lift over

dbSNP: rs1580547770; hg19: chr5-68800093;