rs149308952

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PP3_ModeratePP5

The NM_018941.4(CLN8):​c.470A>G​(p.His157Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,614,022 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H157N) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CLN8
NM_018941.4 missense

Scores

8
9
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:2

Conservation

PhyloP100: 8.66

Publications

3 publications found
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 Gene-Disease associations (from GenCC):
  • neuronal ceroid lipofuscinosis
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • neuronal ceroid lipofuscinosis 8
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P, Orphanet, Ambry Genetics, Myriad Women’s Health
  • neuronal ceroid lipofuscinosis 8 northern epilepsy variant
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
  • autism spectrum disorder
    Inheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 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, 7 uncertain in NM_018941.4
PP3
MetaRNN computational evidence supports a deleterious effect, 0.913
PP5
Variant 8-1771524-A-G is Pathogenic according to our data. Variant chr8-1771524-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 210736.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLN8NM_018941.4 linkc.470A>G p.His157Arg missense_variant Exon 2 of 3 ENST00000331222.6 NP_061764.2 Q9UBY8A0A024QZ57

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CLN8ENST00000331222.6 linkc.470A>G p.His157Arg missense_variant Exon 2 of 3 1 NM_018941.4 ENSP00000328182.4 Q9UBY8
KBTBD11-OT1ENST00000635855.1 linkn.470A>G non_coding_transcript_exon_variant Exon 2 of 30 5 ENSP00000489726.1 A0A1B0GTJ5

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152136
Hom.:
0
Cov.:
32
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:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251458
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000185
AC:
27
AN:
1461886
Hom.:
0
Cov.:
32
AF XY:
0.0000206
AC XY:
15
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000234
AC:
26
AN:
1112012
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000263
AC:
4
AN:
152136
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74332
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41430
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000247
Hom.:
0
Bravo
AF:
0.0000113
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:4Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:2
-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Genome Diagnostics Laboratory, Amsterdam University Medical Center
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Neuronal ceroid lipofuscinosis 8 Pathogenic:1Uncertain:1
Jul 21, 2016
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Jun 22, 2015
Genetic Services Laboratory, University of Chicago
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Neuronal ceroid lipofuscinosis Pathogenic:1Uncertain:1
Mar 09, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces histidine, which is basic and polar, with arginine, which is basic and polar, at codon 157 of the CLN8 protein (p.His157Arg). This variant is present in population databases (rs149308952, gnomAD 0.003%). This missense change has been observed in individual(s) with clinical features of CLN8-related conditions (PMID: 19807737, 29915382). ClinVar contains an entry for this variant (Variation ID: 210736). 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 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. -

Jul 05, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: CLN8 c.470A>G (p.His157Arg) results in a non-conservative amino acid change located in the TRAM/LAG1/CLN8 homology domain (IPR006634) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 251458 control chromosomes. c.470A>G has been reported in the literature in one heterozygous individual affected with Cerebellar Atrophy (Sun_2019), and in one homozygous individual affected with Neuronal Ceroid-Lipofuscinosis (e.g. Kousi_2009, Reinhardt_2010). These data indicate that the variant may be associated with disease. Functional evaluation of the variant protein showed that there was signficantly reduced interaction with lysosomal proteins, with the most pronounced variant effect resulting in <10% of normal activity (di Ronza_2018). The following publications have been ascertained in the context of this evaluation (PMID: 29915382, 19201763, 19807737, 30397314). ClinVar contains an entry for this variant (Variation ID: 210736). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.93
BayesDel_addAF
Pathogenic
0.37
D
BayesDel_noAF
Pathogenic
0.36
CADD
Uncertain
23
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.95
D;D;D;D;.;D;.
Eigen
Uncertain
0.61
Eigen_PC
Uncertain
0.53
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.79
.;.;.;.;T;.;T
M_CAP
Uncertain
0.13
D
MetaRNN
Pathogenic
0.91
D;D;D;D;D;D;D
MetaSVM
Uncertain
0.49
D
MutationAssessor
Uncertain
2.6
M;M;M;M;.;M;.
PhyloP100
8.7
PrimateAI
Uncertain
0.67
T
PROVEAN
Uncertain
-3.5
D;.;.;.;.;.;.
REVEL
Pathogenic
0.89
Sift
Uncertain
0.012
D;.;.;.;.;.;.
Sift4G
Pathogenic
0.0
D;.;.;.;.;.;D
Polyphen
1.0
D;D;D;D;.;D;.
Vest4
0.97
MVP
0.95
MPC
0.30
ClinPred
0.92
D
GERP RS
5.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.41
gMVP
0.92
Mutation Taster
=31/69
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs149308952; hg19: chr8-1719690; API