chr8-1771107-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1PM2

The ENST00000331222.6(CLN8):​c.53A>T​(p.Tyr18Phe) variant causes a missense change. The variant allele was found at a frequency of 0.00019 in 1,613,922 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. Y18C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00020 ( 0 hom. )

Consequence

CLN8
ENST00000331222.6 missense

Scores

3
11
5

Clinical Significance

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

Conservation

PhyloP100: 4.42
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM1
In a chain Protein CLN8 (size 285) in uniprot entity CLN8_HUMAN there are 49 pathogenic changes around while only 20 benign (71%) in ENST00000331222.6
PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
CLN8NM_018941.4 linkuse as main transcriptc.53A>T p.Tyr18Phe missense_variant 2/3 ENST00000331222.6 NP_061764.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
CLN8ENST00000331222.6 linkuse as main transcriptc.53A>T p.Tyr18Phe missense_variant 2/31 NM_018941.4 ENSP00000328182 P1

Frequencies

GnomAD3 genomes
AF:
0.000132
AC:
20
AN:
151910
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000656
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:
0.000265
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000195
AC:
49
AN:
251492
Hom.:
0
AF XY:
0.000169
AC XY:
23
AN XY:
135922
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000298
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000396
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000196
AC:
286
AN:
1461894
Hom.:
0
Cov.:
32
AF XY:
0.000172
AC XY:
125
AN XY:
727248
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.000115
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.0000562
Gnomad4 NFE exome
AF:
0.000245
Gnomad4 OTH exome
AF:
0.000132
GnomAD4 genome
AF:
0.000132
AC:
20
AN:
152028
Hom.:
0
Cov.:
32
AF XY:
0.000135
AC XY:
10
AN XY:
74318
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000265
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000180
Hom.:
0
Bravo
AF:
0.000140
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.000349
AC:
3
ExAC
AF:
0.000255
AC:
31
EpiCase
AF:
0.000218
EpiControl
AF:
0.000178

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingAthena DiagnosticsMar 08, 2018- -
Uncertain significance, criteria provided, single submitterclinical testingGeneDxOct 31, 2024In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Neuronal ceroid lipofuscinosis 8 Uncertain:1
Uncertain significance, no assertion criteria providedclinical testingNatera, Inc.Jan 15, 2020- -
Neuronal ceroid lipofuscinosis Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpAug 20, 2022This sequence change replaces tyrosine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 18 of the CLN8 protein (p.Tyr18Phe). This variant is present in population databases (rs142104002, gnomAD 0.03%). 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: 205202). 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: "Deleterious"; PolyPhen-2: "Benign"; 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. -
Neuronal ceroid lipofuscinosis 8;C1864923:Neuronal ceroid lipofuscinosis 8 northern epilepsy variant Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsDec 16, 2021- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Uncertain
0.015
T
BayesDel_noAF
Uncertain
0.10
CADD
Benign
20
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.64
.;D;D;D;D;.;D;.;.
Eigen
Uncertain
0.33
Eigen_PC
Uncertain
0.27
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.79
T;.;.;.;.;T;.;T;T
M_CAP
Uncertain
0.25
D
MetaRNN
Uncertain
0.47
T;T;T;T;T;T;T;T;T
MetaSVM
Uncertain
0.76
D
MutationAssessor
Uncertain
2.6
.;M;M;M;M;.;M;.;.
MutationTaster
Benign
1.0
D
PrimateAI
Benign
0.47
T
PROVEAN
Benign
-2.1
.;N;.;.;.;.;.;.;.
REVEL
Uncertain
0.64
Sift
Pathogenic
0.0
.;D;.;.;.;.;.;.;.
Sift4G
Pathogenic
0.0
D;D;.;.;.;.;.;D;.
Polyphen
0.99
.;D;D;D;D;.;D;.;.
Vest4
0.39
MVP
0.97
MPC
0.039
ClinPred
0.32
T
GERP RS
4.0
Varity_R
0.29
gMVP
0.61

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.

Other links and lift over

dbSNP: rs142104002; hg19: chr8-1719273; API