chr8-1771113-C-T

Variant summary

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

The NM_018941.4(CLN8):​c.59C>T​(p.Ser20Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000185 in 1,461,888 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. S20T) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CLN8
NM_018941.4 missense

Scores

2
10
7

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.67

Publications

2 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 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLN8NM_018941.4 linkc.59C>T p.Ser20Phe 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.59C>T p.Ser20Phe missense_variant Exon 2 of 3 1 NM_018941.4 ENSP00000328182.4 Q9UBY8
KBTBD11-OT1ENST00000635855.1 linkn.59C>T non_coding_transcript_exon_variant Exon 2 of 30 5 ENSP00000489726.1 A0A1B0GTJ5

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
0.0000185
AC:
27
AN:
1461888
Hom.:
0
Cov.:
32
AF XY:
0.0000179
AC XY:
13
AN XY:
727244
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:
0.0000116
AC:
1
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:
0.0000225
AC:
25
AN:
1112008
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.451
Heterozygous variant carriers
0
2
4
6
8
10
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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

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

Submissions by phenotype

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

This sequence change replaces serine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 20 of the CLN8 protein (p.Ser20Phe). This variant is not present in population databases (gnomAD no frequency). 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: 1442771). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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
0.27
BayesDel_addAF
Pathogenic
0.16
D
BayesDel_noAF
Uncertain
0.0
CADD
Benign
22
DANN
Uncertain
1.0
DEOGEN2
Benign
0.38
.;T;T;T;T;.;T;.;.
Eigen
Uncertain
0.20
Eigen_PC
Benign
0.093
FATHMM_MKL
Uncertain
0.88
D
LIST_S2
Uncertain
0.86
D;.;.;.;.;D;.;D;D
M_CAP
Pathogenic
0.31
D
MetaRNN
Uncertain
0.61
D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.60
D
MutationAssessor
Uncertain
2.5
.;M;M;M;M;.;M;.;.
PhyloP100
2.7
PrimateAI
Benign
0.44
T
PROVEAN
Benign
-1.5
.;N;.;.;.;.;.;.;.
REVEL
Uncertain
0.61
Sift
Benign
0.072
.;T;.;.;.;.;.;.;.
Sift4G
Uncertain
0.027
D;D;.;.;.;.;.;T;.
Polyphen
0.99
.;D;D;D;D;.;D;.;.
Vest4
0.49
MutPred
0.48
Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);
MVP
0.91
MPC
0.14
ClinPred
0.92
D
GERP RS
4.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.048
gMVP
0.74
Mutation Taster
=78/22
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: rs749651452; hg19: chr8-1719279; API