15-68208358-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PM2

The NM_017882.3(CLN6):c.718G>A(p.Ala240Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000868 in 1,613,780 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A240V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

CLN6
NM_017882.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.87

Publications

1 publications found

Variant links:

Genes affected

CLN6 (HGNC:2077): (CLN6 transmembrane ER protein) This gene is one of eight which have been associated with neuronal ceroid lipofuscinoses (NCL). Also referred to as Batten disease, NCL comprises a class of autosomal recessive, neurodegenerative disorders affecting children. The genes responsible likely encode proteins involved in the degradation of post-translationally modified proteins in lysosomes. The primary defect in NCL disorders is thought to be associated with lysosomal storage function. [provided by RefSeq, Oct 2008]

CLN6 Gene-Disease associations (from GenCC):

ceroid lipofuscinosis, neuronal, 6A
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Myriad Women’s Health, Orphanet
ceroid lipofuscinosis, neuronal, 6B (Kufs type)
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
neuronal ceroid lipofuscinosis
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen

CLN6 links:

ENSG00000260007 (HGNC:):

ENSG00000260007 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 12 uncertain in NM_017882.3

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CLN6	NM_017882.3 link	c.718G>A	p.Ala240Thr	missense_variant	Exon 7 of 7	ENST00000249806.11	NP_060352.1
CLN6	NM_001411068.1 link	c.814G>A	p.Ala272Thr	missense_variant	Exon 7 of 7		NP_001397997.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CLN6	ENST00000249806.11 link	c.718G>A	p.Ala240Thr	missense_variant	Exon 7 of 7	1	NM_017882.3	ENSP00000249806.5
ENSG00000260007	ENST00000562767.2 link	c.84-10730G>A		intron_variant	Intron 1 of 2	3		ENSP00000456336.1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152184

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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

GnomAD2 exomes

AF:

0.0000120

AC:

AN:

251024

AF XY:

0.0000147

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000882

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000889

AC:

AN:

1461596

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727096

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53150

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00000540

AC:

AN:

1111998

Other (OTH)

AF:

0.0000662

AC:

AN:

60386

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.498

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152184

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74354

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41438

American (AMR)

AF:

0.00

AC:

AN:

15292

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68030

Other (OTH)

AF:

0.00

AC:

AN:

2094

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Sep 29, 2018

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.A240T variant (also known as c.718G>A), located in coding exon 7 of the CLN6 gene, results from a G to A substitution at nucleotide position 718. The alanine at codon 240 is replaced by threonine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Dec 23, 2015

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

A variant of uncertain significance has been identified in the CLN6 gene. The A240T variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The A240T variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size, and/or other properties. This substitution occurs at a position that is conserved in mammals and is predicted to be within the sixth transmembrane domain of the CLN6 protein (Kousi et al., 2012); however, Threonine is observed at this position in evolution. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Neuronal ceroid lipofuscinosis

Uncertain:1

Dec 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 240 of the CLN6 protein (p.Ala240Thr). This variant is present in population databases (rs779105796, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with CLN6-related conditions. ClinVar contains an entry for this variant (Variation ID: 420280). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt CLN6 protein function with a negative predictive value of 80%. 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

0.18

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Uncertain

0.12

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.84

D;D;D;.;T;T

Eigen

Benign

-0.025

Eigen_PC

Benign

0.096

FATHMM_MKL

Uncertain

0.88

LIST_S2

Uncertain

0.87

D;D;D;D;D;D

M_CAP

Uncertain

0.15

MetaRNN

Uncertain

0.52

D;D;D;D;D;D

MetaSVM

Uncertain

0.37

MutationAssessor

Benign

1.6

L;.;.;.;.;.

PhyloP100

3.9

PrimateAI

Uncertain

0.62

PROVEAN

Benign

-2.2

N;D;N;N;.;.

REVEL

Pathogenic

0.66

Sift

Benign

0.18

T;T;T;T;.;.

Sift4G

Benign

0.13

T;D;D;T;.;.

Polyphen

0.13

B;.;.;.;.;.

Vest4

0.44

MutPred

0.50

.;.;.;Loss of catalytic residue at A272 (P = 0.1976);.;.;

MVP

0.93

MPC

0.30

ClinPred

0.47

GERP RS

4.4

Varity_R

0.17

gMVP

0.76

Mutation Taster

=49/51

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over