rs34030778

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The NM_018941.4(CLN8):​c.274C>G​(p.His92Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. 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. H92Y) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

CLN8
NM_018941.4 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.29

Publications

7 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 2 ACMG points.

PM1
In a domain TLC (size 200) in uniprot entity CLN8_HUMAN there are 23 pathogenic changes around while only 9 benign (72%) in NM_018941.4
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.08893439).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLN8NM_018941.4 linkc.274C>G p.His92Asp 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.274C>G p.His92Asp missense_variant Exon 2 of 3 1 NM_018941.4 ENSP00000328182.4 Q9UBY8
KBTBD11-OT1ENST00000635855.1 linkn.274C>G non_coding_transcript_exon_variant Exon 2 of 30 5 ENSP00000489726.1 A0A1B0GTJ5

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461892
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
727246
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:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Neuronal ceroid lipofuscinosis Uncertain:1
Aug 19, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. 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. ClinVar contains an entry for this variant (Variation ID: 834230). This variant has not been reported in the literature in individuals affected with CLN8-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces histidine, which is basic and polar, with aspartic acid, which is acidic and polar, at codon 92 of the CLN8 protein (p.His92Asp). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.18
BayesDel_addAF
Benign
-0.082
T
BayesDel_noAF
Benign
-0.36
CADD
Benign
6.2
DANN
Benign
0.83
DEOGEN2
Benign
0.37
.;T;T;T;T;.;T;.
Eigen
Benign
-0.82
Eigen_PC
Benign
-0.82
FATHMM_MKL
Benign
0.15
N
LIST_S2
Benign
0.75
T;.;.;.;.;T;.;T
M_CAP
Uncertain
0.088
D
MetaRNN
Benign
0.089
T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.74
T
MutationAssessor
Benign
1.2
.;L;L;L;L;.;L;.
PhyloP100
1.3
PrimateAI
Uncertain
0.56
T
PROVEAN
Benign
-0.25
.;N;.;.;.;.;.;.
REVEL
Benign
0.050
Sift
Benign
0.26
.;T;.;.;.;.;.;.
Sift4G
Benign
0.21
.;T;.;.;.;.;.;T
Polyphen
0.049
.;B;B;B;B;.;B;.
Vest4
0.42
MutPred
0.27
Gain of disorder (P = 0.0562);Gain of disorder (P = 0.0562);Gain of disorder (P = 0.0562);Gain of disorder (P = 0.0562);Gain of disorder (P = 0.0562);Gain of disorder (P = 0.0562);Gain of disorder (P = 0.0562);Gain of disorder (P = 0.0562);
MVP
0.73
MPC
0.051
ClinPred
0.064
T
GERP RS
2.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.026
gMVP
0.47
Mutation Taster
=82/18
polymorphism

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: rs34030778; hg19: chr8-1719494; API