8-1780325-C-G

Position:

chr8-1780325-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The NM_018941.4(CLN8):c.619C>G(p.Leu207Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000353 in 1,614,272 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CLN8
NM_018941.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 2.26

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 10 uncertain in NM_018941.4

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.18093738).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLN8	NM_018941.4 linkuse as main transcript	c.619C>G	p.Leu207Val	missense_variant	3/3	ENST00000331222.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CLN8	ENST00000331222.6 linkuse as main transcript	c.619C>G	p.Leu207Val	missense_variant	3/3	1	NM_018941.4	P1

Frequencies

GnomAD3 genomes

AF:

0.000197

AC:

AN:

152266

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000627

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.000478

GnomAD3 exomes

AF:

0.0000517

AC:

AN:

251408

Hom.:

AF XY:

0.0000515

AC XY:

AN XY:

135896

show subpopulations

Gnomad AFR exome

AF:

0.000738

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000185

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.000388

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000450

Gnomad4 OTH exome

AF:

0.000116

GnomAD4 genome

AF:

0.000197

AC:

AN:

152384

Hom.:

Cov.:

AF XY:

0.000242

AC XY:

AN XY:

74514

show subpopulations

Gnomad4 AFR

AF:

0.000625

Gnomad4 AMR

AF:

0.000196

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:

0.000473

Alfa

AF:

0.0000755

Hom.:

Bravo

AF:

0.000219

ESP6500AA

AF:

0.00113

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000741

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 29, 2018

The p.L207V variant (also known as c.619C>G), located in coding exon 2 of the CLN8 gene, results from a C to G substitution at nucleotide position 619. The leucine at codon 207 is replaced by valine, an amino acid with highly similar properties. A variant in the same codon, p.L207R, has been described in the homozygous state in a child with neuronal ceroid lipofuscinosis (Katata Y et al. Brain Dev., 2016 Mar;38:341-5). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on available evidence to date, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

May 06, 2021

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Neuronal ceroid lipofuscinosis 8

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Jan 24, 2020

- -

Neuronal ceroid lipofuscinosis

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 26, 2022

This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 207 of the CLN8 protein (p.Leu207Val). This variant is present in population databases (rs151334741, gnomAD 0.07%). This variant has not been reported in the literature in individuals affected with CLN8-related conditions. ClinVar contains an entry for this variant (Variation ID: 451285). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt CLN8 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Seizure

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

New York Genome Center

Jan 23, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.19

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.39

T;T;T;T;T

Eigen

Benign

0.15

Eigen_PC

Benign

0.072

FATHMM_MKL

Uncertain

0.83

M_CAP

Benign

0.039

MetaRNN

Benign

0.18

T;T;T;T;T

MetaSVM

Uncertain

0.16

MutationAssessor

Uncertain

2.2

M;M;M;M;M

MutationTaster

Benign

0.99

PrimateAI

Uncertain

0.62

PROVEAN

Benign

-0.38

N;.;.;.;.

REVEL

Uncertain

0.38

Sift

Benign

0.20

T;.;.;.;.

Sift4G

Benign

0.067

T;.;.;.;.

Polyphen

0.97

D;D;D;D;D

Vest4

0.25

MVP

0.87

MPC

0.059

ClinPred

0.071

GERP RS

3.0

Varity_R

0.035

gMVP

0.75

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

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