chr8-1780367-G-A

Variant names:

Variant summary

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

The NM_018941.4(CLN8):c.661G>A(p.Gly221Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000465 in 1,614,112 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000048 ( 0 hom. )

Consequence

CLN8
NM_018941.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:5

Conservation

PhyloP100: 0.208

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:

KBTBD11-OT1 (HGNC:):

KBTBD11-OT1 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 domain TLC (size 200) in uniprot entity CLN8_HUMAN there are 17 pathogenic changes around while only 5 benign (77%) in NM_018941.4

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.10582662).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CLN8	NM_018941.4 link	c.661G>A	p.Gly221Ser	missense_variant	Exon 3 of 3	ENST00000331222.6	NP_061764.2	Q9UBY8A0A024QZ57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CLN8	ENST00000331222.6 link	c.661G>A	p.Gly221Ser	missense_variant	Exon 3 of 3	1	NM_018941.4	ENSP00000328182.4		Q9UBY8
KBTBD11-OT1	ENST00000635855.1 link	n.543+8770G>A		intron_variant	Intron 2 of 29	5		ENSP00000489726.1		A0A1B0GTJ5

Frequencies

GnomAD3 genomes

AF:

0.0000328

AC:

AN:

152218

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000437

AC:

AN:

251482

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135920

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000924

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000479

AC:

AN:

1461894

Hom.:

Cov.:

AF XY:

0.0000523

AC XY:

AN XY:

727248

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000749

Gnomad4 NFE exome

AF:

0.0000495

Gnomad4 OTH exome

AF:

0.0000828

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152218

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74366

show subpopulations

Gnomad4 AFR

AF:

0.0000965

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000709

Hom.:

Bravo

AF:

0.0000302

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Neuronal ceroid lipofuscinosis 8

Pathogenic:1Uncertain:1

Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Mar 10, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided

Uncertain:2

Dec 15, 2017

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 12, 2017

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Uncertain:1

Dec 01, 2021

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CLN8 c.661G>A (p.Gly221Ser) results in a non-conservative amino acid change located in the TRAM/LAG1/CLN8 homology domain (IPR006634) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4.4e-05 in 251482 control chromosomes (gnomAD). This frequency is lower than the maximum expected for a pathogenic variant in CLN8 causing Neuronal Ceroid-Lipofuscinosis (Batten Disease) (0.00087), allowing no conclusion about variant significance. c.661G>A has been reported in the literature in an individual affected with Neuronal Ceroid-Lipofuscinosis (Batten Disease), however no phenotype details were provided (Kousi_2012). This report does not provide unequivocal conclusions about association of the variant with Neuronal Ceroid-Lipofuscinosis (Batten Disease). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Neuronal ceroid lipofuscinosis

Uncertain:1

Jul 23, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 221 of the CLN8 protein (p.Gly221Ser). This variant is present in population databases (rs386834136, gnomAD 0.01%). This missense change has been observed in individual(s) with late infantile neuronal ceroid lipofucinosis (PMID: 21990111). ClinVar contains an entry for this variant (Variation ID: 56717). 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.078

BayesDel_addAF

Benign

-0.074

BayesDel_noAF

Benign

-0.11

CADD

Benign

2.3

DANN

Benign

0.80

DEOGEN2

Benign

0.32

T;T;T;T;T

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.16

M_CAP

Benign

0.052

MetaRNN

Benign

0.11

T;T;T;T;T

MetaSVM

Benign

-0.87

MutationAssessor

Benign

1.0

L;L;L;L;L

PrimateAI

Benign

0.24

PROVEAN

Benign

0.40

N;.;.;.;.

REVEL

Uncertain

0.54

Sift

Benign

0.75

T;.;.;.;.

Sift4G

Benign

0.73

T;.;.;.;.

Polyphen

0.11

B;B;B;B;B

Vest4

0.66

MVP

0.72

MPC

0.040

ClinPred

0.013

GERP RS

-0.016

Varity_R

0.021

gMVP

0.43

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