rs758068226

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP3

The NM_018941.4(CLN8):​c.94T>C​(p.Phe32Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,614,070 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F32V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

CLN8
NM_018941.4 missense

Scores

5
10
4

Clinical Significance

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

Conservation

PhyloP100: 7.23

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 3 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 18 uncertain in NM_018941.4
PP3
MetaRNN computational evidence supports a deleterious effect, 0.79

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLN8NM_018941.4 linkc.94T>C p.Phe32Leu 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.94T>C p.Phe32Leu missense_variant Exon 2 of 3 1 NM_018941.4 ENSP00000328182.4 Q9UBY8
KBTBD11-OT1ENST00000635855.1 linkn.94T>C non_coding_transcript_exon_variant Exon 2 of 30 5 ENSP00000489726.1 A0A1B0GTJ5

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152066
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:
0.000388
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:
0.0000239
AC:
6
AN:
251478
AF XY:
0.0000294
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000272
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000547
AC:
8
AN:
1461886
Hom.:
0
Cov.:
32
AF XY:
0.00000825
AC XY:
6
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:
0.000151
AC:
6
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:
8.99e-7
AC:
1
AN:
1112006
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000197
AC:
3
AN:
152184
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74412
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41538
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000389
AC:
2
AN:
5140
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:1
Aug 29, 2019
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Neuronal ceroid lipofuscinosis 8 Uncertain:1
Sep 02, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Neuronal ceroid lipofuscinosis Uncertain:1
Sep 01, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces phenylalanine with leucine at codon 32 of the CLN8 protein (p.Phe32Leu). The phenylalanine residue is highly conserved and there is a small physicochemical difference between phenylalanine and leucine. This variant is present in population databases (rs758068226, ExAC 0.01%). 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: 241290). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.88
BayesDel_addAF
Uncertain
0.065
T
BayesDel_noAF
Pathogenic
0.15
CADD
Uncertain
23
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.64
.;D;D;D;D;.;D;.;.
Eigen
Uncertain
0.24
Eigen_PC
Uncertain
0.24
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.82
T;.;.;.;.;T;.;T;T
M_CAP
Uncertain
0.12
D
MetaRNN
Pathogenic
0.79
D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.38
D
MutationAssessor
Uncertain
2.6
.;M;M;M;M;.;M;.;.
PhyloP100
7.2
PrimateAI
Uncertain
0.61
T
PROVEAN
Uncertain
-3.3
.;D;.;.;.;.;.;.;.
REVEL
Pathogenic
0.73
Sift
Benign
0.19
.;T;.;.;.;.;.;.;.
Sift4G
Benign
0.079
T;T;.;.;.;.;.;T;.
Polyphen
0.95
.;P;P;P;P;.;P;.;.
Vest4
0.75
MutPred
0.63
Loss of helix (P = 0.079);Loss of helix (P = 0.079);Loss of helix (P = 0.079);Loss of helix (P = 0.079);Loss of helix (P = 0.079);Loss of helix (P = 0.079);Loss of helix (P = 0.079);Loss of helix (P = 0.079);Loss of helix (P = 0.079);
MVP
0.97
MPC
0.093
ClinPred
0.38
T
GERP RS
5.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.26
gMVP
0.76
Mutation Taster
=39/61
disease causing

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: rs758068226; hg19: chr8-1719314; API