rs386834139

Positions:

• chr8-1771141-CG-C

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_018941.4(CLN8):​c.88del​(p.Ala30LeufsTer20) 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 Likely pathogenic (no stars). Synonymous variant affecting the same amino acid position (i.e. A30A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CLN8 NM_018941.4 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic no assertion criteria provided P:2
• Conservation: PhyloP100: 3.47

Genes affected

CLN8 (HGNC:2079): (CLN8 transmembrane ER and ERGIC protein) This gene encodes a transmembrane protein belonging to a family of proteins containing TLC domains, which are postulated to function in lipid synthesis, transport, or sensing. The protein localizes to the endoplasmic reticulum (ER), and may recycle between the ER and ER-Golgi intermediate compartment. Mutations in this gene are associated with a disorder characterized by progressive epilepsy with cognitive disabilities (EPMR), which is a subtype of neuronal ceroid lipofuscinoses (NCL). Patients with mutations in this gene have altered levels of sphingolipid and phospholipids in the brain. [provided by RefSeq, Jul 2017]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 70 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-1771141-CG-C is Pathogenic according to our data. Variant chr8-1771141-CG-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 56720.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr8-1771141-CG-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLN8	NM_018941.4	c.88del	p.Ala30LeufsTer20	frameshift_variant	2/3	ENST00000331222.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CLN8	ENST00000331222.6	c.88del	p.Ala30LeufsTer20	frameshift_variant	2/3	1	NM_018941.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: no assertion criteria provided

Submissions by phenotype

Neuronal ceroid lipofuscinosis 8 Pathogenic:2

Likely pathogenic, no assertion criteria provided	literature only	Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)	-	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Jan 01, 2001	- -

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: rs386834139; hg19: chr8-1719307;