chr6-145735264-C-G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM1BP4_StrongBS1_Supporting

The NM_005670.4(EPM2A):c.235G>C(p.Gly79Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000646 in 1,517,924 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. G79C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00036 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000031 ( 0 hom. )

Consequence

EPM2A
NM_005670.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5B:1

Conservation

PhyloP100: 0.0390

Publications

2 publications found

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:

ENSG00000288551 (HGNC:):

ENSG00000288551 links:

EPM2A-DT (HGNC:48990): (EPM2A divergent transcript)

EPM2A-DT links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 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, 14 uncertain in NM_005670.4

BP4

Computational evidence support a benign effect (MetaRNN=0.05141419).

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000363 (55/151558) while in subpopulation AFR AF = 0.00123 (51/41504). AF 95% confidence interval is 0.000959. There are 0 homozygotes in GnomAd4. There are 18 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
EPM2A	NM_005670.4 link	c.235G>C	p.Gly79Arg	missense_variant	Exon 1 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.235G>C	p.Gly79Arg	missense_variant	Exon 1 of 4	1	NM_005670.4	ENSP00000356489.3		O95278-1

Frequencies

GnomAD3 genomes

AF:

0.000363

AC:

AN:

151450

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00123

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.000961

GnomAD2 exomes

AF:

0.0000513

AC:

AN:

136456

AF XY:

0.0000133

show subpopulations

Gnomad AFR exome

AF:

0.00122

Gnomad AMR exome

AF:

0.0000440

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000315

AC:

AN:

1366366

Hom.:

Cov.:

AF XY:

0.0000222

AC XY:

AN XY:

675480

show subpopulations

African (AFR)

AF:

0.00130

AC:

AN:

28530

American (AMR)

AF:

0.0000294

AC:

AN:

33970

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

23552

East Asian (EAS)

AF:

0.00

AC:

AN:

32294

South Asian (SAS)

AF:

0.00

AC:

AN:

76918

European-Finnish (FIN)

AF:

0.00

AC:

AN:

46140

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5374

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1063776

Other (OTH)

AF:

0.0000896

AC:

AN:

55812

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.460

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.000363

AC:

AN:

151558

Hom.:

Cov.:

AF XY:

0.000243

AC XY:

AN XY:

74078

show subpopulations

African (AFR)

AF:

0.00123

AC:

AN:

41504

American (AMR)

AF:

0.000131

AC:

AN:

15234

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3462

East Asian (EAS)

AF:

0.00

AC:

AN:

5132

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10356

Middle Eastern (MID)

AF:

0.00

AC:

AN:

292

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67728

Other (OTH)

AF:

0.000951

AC:

AN:

2104

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.486

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000229

Hom.:

Bravo

AF:

0.000563

ESP6500AA

AF:

0.000469

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000718

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5Benign:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Nov 11, 2014

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 15, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Lafora disease

Uncertain:1

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Inborn genetic diseases

Uncertain:1

Aug 01, 2018

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.G79R variant (also known as c.235G>C), located in coding exon 1 of the EPM2A gene, results from a G to C substitution at nucleotide position 235. The glycine at codon 79 is replaced by arginine, an amino acid with dissimilar properties. This amino acid position is well conserved on limited sequence alignment. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear. -

Progressive myoclonic epilepsy

Uncertain:1

Oct 18, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 79 of the EPM2A protein (p.Gly79Arg). This variant is present in population databases (rs374826256, gnomAD 0.2%). This variant has not been reported in the literature in individuals affected with EPM2A-related conditions. ClinVar contains an entry for this variant (Variation ID: 193326). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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. -

EPM2A-related disorder

Benign:1

Apr 08, 2024

PreventionGenetics, part of Exact Sciences

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.21

BayesDel_addAF

Benign

-0.084

BayesDel_noAF

Uncertain

0.090

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Uncertain

0.42

T;.;.;.

Eigen

Benign

-0.24

Eigen_PC

Benign

-0.23

FATHMM_MKL

Uncertain

0.79

LIST_S2

Benign

0.77

T;T;.;T

M_CAP

Pathogenic

0.89

MetaRNN

Benign

0.051

T;T;T;T

MetaSVM

Uncertain

0.16

MutationAssessor

Benign

1.7

L;L;L;L

PhyloP100

0.039

PrimateAI

Pathogenic

0.81

PROVEAN

Benign

-0.74

N;.;.;.

REVEL

Uncertain

0.55

Sift

Benign

0.36

T;.;.;.

Sift4G

Benign

0.27

T;T;.;.

Polyphen

0.26

B;B;B;.

Vest4

0.16

MVP

0.96

MPC

0.37

ClinPred

0.12

GERP RS

2.2

PromoterAI

-0.0060

Neutral

(source)

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

gMVP

0.49

Mutation Taster

=86/14

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over