Variant chr8-1763857-GCAGGGAGCCCGGCTGAGTGGCAGCCCAGGTGAGCGCT-G details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_StrongPM2

The NM_018941.4(CLN8):c.-139_-124+21del variant causes a splice donor, splice donor 5th base, 5 prime UTR, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000661 in 151,210 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 27)

Consequence

CLN8
NM_018941.4 splice_donor, splice_donor_5th_base, 5_prime_UTR, intron

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.61

Variant links:

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]

CLN8 links:

CLN8-AS1 (HGNC:55523): (CLN8 antisense RNA 1)

CLN8-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.11149826 fraction of the gene. Cryptic splice site detected, with MaxEntScore 10, offset of 3, new splice context is: cagGTgagg. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLN8	NM_018941.4 linkuse as main transcript	c.-139_-124+21del		splice_donor_variant, splice_donor_5th_base_variant, 5_prime_UTR_variant, intron_variant	1/3	ENST00000331222.6
CLN8-AS1	NR_134303.1 linkuse as main transcript	n.151+540_151+576del		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CLN8	ENST00000331222.6 linkuse as main transcript	c.-139_-124+21del		splice_donor_variant, splice_donor_5th_base_variant, 5_prime_UTR_variant, intron_variant	1/3	1	NM_018941.4	P1
CLN8-AS1	ENST00000659375.1 linkuse as main transcript	n.75+540_75+576del		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.00000661

AC:

AN:

151210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000243

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:

0.00

Gnomad OTH

AF:

0.00

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome

AF:

0.00000661

AC:

AN:

151210

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

73820

show subpopulations

Gnomad4 AFR

AF:

0.0000243

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Feb 16, 2017

A variant of uncertain significance has been identified in the CLN8 gene. The c. -139_-124+21del37 variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. No data are available from control populations to assess the frequency of this variant. This variant spans the 3' end of the noncoding exon 1 and the donor site of intron 2. Several in-silico splice prediction models predict that c. -139_-124+21del37 variant may destroy the natural donor site and lead to abnormal gene splicing. However, in the absence of RNA/functional studies, the actual effect of this sequence change in this individual is unknown. Additionally, to our knowledge, splice and regulatory variants have not been reported in CLN8 in association with NCL (Stenson et al., 2014). Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over