chr6-145735429-C-A

Position:

chr6-145735429-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_005670.4(EPM2A):c.70G>T(p.Gly24Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000663 in 150,794 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. G24R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

EPM2A
NM_005670.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.43

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:

EPM2A-DT (HGNC:):

EPM2A-DT links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_005670.4

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.875

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
EPM2A	NM_005670.4 linkuse as main transcript	c.70G>T	p.Gly24Trp	missense_variant	1/4	ENST00000367519.9
EPM2A-DT	NR_038246.1 linkuse as main transcript	n.52+509C>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
EPM2A	ENST00000367519.9 linkuse as main transcript	c.70G>T	p.Gly24Trp	missense_variant	1/4	1	NM_005670.4	P1	O95278-1

Frequencies

GnomAD3 genomes

AF:

0.00000663

AC:

AN:

150794

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

1106792

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

533866

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000663

AC:

AN:

150794

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

73602

show subpopulations

Gnomad4 AFR

AF:

0.0000242

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:

0.00

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Progressive myoclonic epilepsy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 27, 2021

This sequence change replaces glycine with tryptophan at codon 24 of the EPM2A protein (p.Gly24Trp). The glycine residue is moderately conserved and there is a large physicochemical difference between glycine and tryptophan. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the ExAC database. This variant has not been reported in the literature in individuals affected with EPM2A-related conditions. 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: "Probably Damaging"; 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

BayesDel_addAF

Pathogenic

0.36

BayesDel_noAF

Pathogenic

0.29

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.86

D;.;.;.

Eigen

Uncertain

0.45

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Uncertain

0.88

LIST_S2

Benign

0.81

T;T;.;T

M_CAP

Pathogenic

0.94

MetaRNN

Pathogenic

0.87

D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.5

M;M;M;M

MutationTaster

Benign

1.0

PrimateAI

Pathogenic

0.93

PROVEAN

Uncertain

-3.4

D;.;.;.

REVEL

Pathogenic

0.85

Sift

Pathogenic

0.0

D;.;.;.

Sift4G

Pathogenic

0.0

D;D;.;.

Polyphen

1.0

D;D;D;.

Vest4

0.40

MutPred

0.64

Loss of disorder (P = 0.0018);Loss of disorder (P = 0.0018);Loss of disorder (P = 0.0018);Loss of disorder (P = 0.0018);

MVP

0.99

MPC

0.95

ClinPred

0.99

GERP RS

2.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

gMVP

0.83

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.

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