rs137852916

Variant names:

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

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]

EPM2A links:

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
EPM2A	NM_005670.4 link	c.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
EPM2A	ENST00000367519.9 link	c.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:

AN:

152164

Hom.:

Cov.:

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:

AN:

251448

Hom.:

AF XY:

0.0000294

AC XY:

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:

AN:

1461652

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

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:

AN:

152164

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

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.:

Bravo

AF:

0.0000189

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000330

AC:

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

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). -

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

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

BayesDel_noAF

Pathogenic

0.37

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.64

.;D;.;.;.;.;.;.;.

Eigen

Uncertain

0.52

Eigen_PC

Uncertain

0.62

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.97

D;D;.;D;.;.;.;.;D

M_CAP

Benign

0.055

MetaRNN

Pathogenic

0.84

D;D;D;D;D;D;D;D;D

MetaSVM

Benign

-0.72

MutationAssessor

Uncertain

2.3

.;M;.;M;.;M;.;.;.

PrimateAI

Uncertain

0.68

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

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over