NM_005670.4:c.512G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PP3_ModeratePP5_Moderate

The NM_005670.4(EPM2A):​c.512G>A​(p.Arg171His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000143 in 1,613,816 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 Likely pathogenic (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

EPM2A
NM_005670.4 missense

Scores

7
7
4

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:4O:1

Conservation

PhyloP100: 7.57
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 8 ACMG points.

PM1
In a mutagenesis_site No effect on phosphatase activity. (size 0) in uniprot entity EPM2A_HUMAN
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.842
PP5
Variant 6-145635451-C-T is Pathogenic according to our data. Variant chr6-145635451-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3102.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.512G>A p.Arg171His missense_variant Exon 3 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.512G>A p.Arg171His missense_variant Exon 3 of 4 1 NM_005670.4 ENSP00000356489.3 O95278-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152164
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.0000199
AC:
5
AN:
251448
Hom.:
0
AF XY:
0.0000294
AC XY:
4
AN XY:
135900
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:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000144
AC:
21
AN:
1461652
Hom.:
0
Cov.:
30
AF XY:
0.0000151
AC XY:
11
AN XY:
727164
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000153
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152164
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74326
show subpopulations
Gnomad4 AFR
AF:
0.00
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:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.00000961
Hom.:
0
Bravo
AF:
0.0000189
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000330
AC:
4
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:4Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Lafora disease Pathogenic:1Other:1
-
GeneReviews
Significance: not provided
Review Status: no classification provided
Collection Method: literature only

- -

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.Arg171His variant in EPM2A has been reported in five individuals with Lafora disease (PMID: 9931343, 10932264, 12019207, 14722920, 34568804), and has been identified in in 0.003% (1/62476) of East Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs137852916). Although this variant has been seen in the general population in a heterozygous state, its frequency is not high enough to rule out a pathogenic role. This variant has also been reported in ClinVar (Variation ID: 3102) and has been interpreted as a variant of uncertain significance by Invitae and as pathogenic by OMIM. Of the five affected individuals, two of those were homozygotes, which increases the likelihood that the p.Arg171His variant is pathogenic (PMID: 34568804, 9931343). In vitro functional studies provide some evidence that the p.Arg171His variant may slightly impact protein function (PMID: 11001928, 25544560). 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 phenotypes of two individuals compound heterozygous or homozygous for this variant are highly specific for Lafora disease based on Lafora bodies identified via biopsy consistent with disease (PMID: 11175283, 10932264, 34568804). 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: PP3_moderate, PP4, PM2_supporting, PM3, PS3_supporting (Richards 2015). -

not provided Pathogenic:1
Jan 20, 2022
Genetics and Genomic Medicine Centre, NeuroGen Healthcare, NeuroGen Healthcare
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Progressive myoclonic epilepsy Pathogenic:1
Apr 14, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 171 of the EPM2A protein (p.Arg171His). This variant is present in population databases (rs137852916, gnomAD 0.004%). This missense change has been observed in individual(s) with Lafora disease (PMID: 9931343, 10932264, 12019207, 34568804). ClinVar contains an entry for this variant (Variation ID: 3102). 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) has been performed at Invitae 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 have shown that this missense change affects EPM2A function (PMID: 25544560). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely 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
0.35
D
BayesDel_noAF
Pathogenic
0.37
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.64
.;D;.;.;.;.;.;.;.
Eigen
Uncertain
0.52
Eigen_PC
Uncertain
0.62
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.97
D;D;.;D;.;.;.;.;D
M_CAP
Benign
0.055
D
MetaRNN
Pathogenic
0.84
D;D;D;D;D;D;D;D;D
MetaSVM
Benign
-0.72
T
MutationAssessor
Uncertain
2.3
.;M;.;M;.;M;.;.;.
PrimateAI
Uncertain
0.68
T
PROVEAN
Uncertain
-2.6
.;D;.;.;.;.;.;.;.
REVEL
Pathogenic
0.78
Sift
Pathogenic
0.0
.;D;.;.;.;.;.;.;.
Sift4G
Benign
0.066
.;T;.;T;T;.;.;.;.
Polyphen
1.0
.;D;.;D;.;D;.;.;.
Vest4
0.96, 0.97, 0.94
MVP
0.93
MPC
0.96
ClinPred
0.98
D
GERP RS
5.9
gMVP
0.84

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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: rs137852916; hg19: chr6-145956587; COSMIC: COSV62296557; COSMIC: COSV62296557; API