rs137852915

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_ModeratePP5_Moderate

The NM_001360064.2(EPM2A):​c.-93C>T variant causes a 5 prime UTR premature start codon gain change. The variant allele was found at a frequency of 0.0000229 in 1,613,626 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 Pathogenic (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

EPM2A
NM_001360064.2 5_prime_UTR_premature_start_codon_gain

Scores

10
7
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 4.12
Variant links:
Genes affected
EPM2A (HGNC:3413): (EPM2A glucan phosphatase, laforin) This gene encodes a dual-specificity phosphatase and may be involved in the regulation of glycogen metabolism. The protein acts on complex carbohydrates to prevent glycogen hyperphosphorylation, thus avoiding the formation of insoluble aggregates. Loss-of-function mutations in this gene have been associated with Lafora disease, a rare, adult-onset recessive neurodegenerative disease, which results in myoclonus epilepsy and usually results in death several years after the onset of symptoms. The disease is characterized by the accumulation of insoluble particles called Lafora bodies, which are derived from glycogen. [provided by RefSeq, Jan 2018]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.887
PP5
Variant 6-145686276-G-A is Pathogenic according to our data. Variant chr6-145686276-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 3100.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
EPM2ANM_005670.4 linkc.322C>T p.Arg108Cys missense_variant Exon 2 of 4 ENST00000367519.9 NP_005661.1 O95278-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
EPM2AENST00000367519.9 linkc.322C>T p.Arg108Cys missense_variant Exon 2 of 4 1 NM_005670.4 ENSP00000356489.3 O95278-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152100
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000239
AC:
6
AN:
251372
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135866
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000440
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000246
AC:
36
AN:
1461526
Hom.:
0
Cov.:
32
AF XY:
0.0000234
AC XY:
17
AN XY:
727092
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000306
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152100
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74286
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000756
ExAC
AF:
0.0000330
AC:
4
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Lafora disease Pathogenic:1
Jan 06, 2025
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: curation

The p.Arg108Cys variant in EPM2A has been reported in at least two individuals with Lafora disease (PMID: 9771710, 11175283, 12019207, 25270369), and has been identified in 0.003% (35/1179790) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs137852915). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (Variation ID: 3100) and has been interpreted as pathogenic by OMIM and Invitae. Of the affected individuals, at least 1 was a homozygote, and 1 was a compound heterozygote that carried a reported pathogenic variant with unknown phase, which increases the likelihood that the p.Arg108Cys variant is pathogenic (PMID: 9771710, 12019207, 25270369). In vitro functional studies provide some evidence that the p.Arg108Cys variant may impact protein function (PMID: 12019207, 14532330, 14706656, 18029386, 19403557). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. The phenotype of individuals homozygous for this variant are highly specific for Lafora disease based on biopsies showing Lafora bodies consistent with disease (PMID: 9771710, 12019207). In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal recessive Lafora disease. ACMG/AMP Criteria applied: PP4, PM3, PP3_moderate, PM2_supporting, PS3_supporting (Richards 2015). -

Progressive myoclonic epilepsy Pathogenic:1
Oct 31, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 108 of the EPM2A protein (p.Arg108Cys). This variant is present in population databases (rs137852915, gnomAD 0.004%). This missense change has been observed in individual(s) with Lafora disease (PMID: 9771710, 11175283). This variant is also known as R107C. ClinVar contains an entry for this variant (Variation ID: 3100). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on EPM2A protein function. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on EPM2A function (PMID: 12019207, 14532330, 14706656, 19403557). For these reasons, this variant has been classified as Pathogenic. -

Myoclonic epilepsy of Lafora 1 Pathogenic:1
Oct 01, 2005
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.33
D
BayesDel_noAF
Pathogenic
0.37
CADD
Pathogenic
30
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.46
T;.;.;.
Eigen
Pathogenic
0.74
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D;D;.;D
M_CAP
Uncertain
0.25
D
MetaRNN
Pathogenic
0.89
D;D;D;D
MetaSVM
Uncertain
0.68
D
MutationAssessor
Uncertain
2.6
M;M;M;M
PrimateAI
Pathogenic
0.79
T
PROVEAN
Uncertain
-3.4
D;.;.;.
REVEL
Pathogenic
0.80
Sift
Uncertain
0.0010
D;.;.;.
Sift4G
Pathogenic
0.0
D;D;.;.
Polyphen
1.0
D;D;D;.
Vest4
0.93
MutPred
0.74
Loss of disorder (P = 0.0543);Loss of disorder (P = 0.0543);Loss of disorder (P = 0.0543);Loss of disorder (P = 0.0543);
MVP
0.96
MPC
1.0
ClinPred
0.90
D
GERP RS
5.8
gMVP
0.87

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: rs137852915; hg19: chr6-146007412; COSMIC: COSV62295254; COSMIC: COSV62295254; API