6-145627450-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP3

The NM_005670.4(EPM2A):ā€‹c.962T>Gā€‹(p.Phe321Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000157 in 1,461,894 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (ā˜…).

Frequency

Genomes: not found (cov: 33)
Exomes š‘“: 0.000016 ( 1 hom. )

Consequence

EPM2A
NM_005670.4 missense

Scores

9
7
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.95
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM1
In a mutagenesis_site Impairs protein stability. Strongly reduces phosphatase activity. No effect on glycogen binding. (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, 0.835

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
EPM2ANM_005670.4 linkuse as main transcriptc.962T>G p.Phe321Cys missense_variant 4/4 ENST00000367519.9 NP_005661.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
EPM2AENST00000367519.9 linkuse as main transcriptc.962T>G p.Phe321Cys missense_variant 4/41 NM_005670.4 ENSP00000356489 P1O95278-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD3 exomes
AF:
0.0000358
AC:
9
AN:
251490
Hom.:
0
AF XY:
0.0000441
AC XY:
6
AN XY:
135920
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000294
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000157
AC:
23
AN:
1461894
Hom.:
1
Cov.:
32
AF XY:
0.0000234
AC XY:
17
AN XY:
727248
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.000267
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
33
ExAC
AF:
0.00000824
AC:
1

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 submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpMar 25, 2021In 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. 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"). This variant has been observed in individual(s) with clinical features of progressive myoclonic epilepsy (PMID: 27574708). This variant is present in population databases (rs772620616, ExAC 0.006%). This sequence change replaces phenylalanine with cysteine at codon 321 of the EPM2A protein (p.Phe321Cys). The phenylalanine residue is highly conserved and there is a large physicochemical difference between phenylalanine and cysteine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Pathogenic
0.34
CADD
Pathogenic
26
DANN
Uncertain
0.99
DEOGEN2
Benign
0.32
T;.;.;.;.;.
Eigen
Uncertain
0.59
Eigen_PC
Uncertain
0.54
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.90
D;.;.;.;.;D
M_CAP
Pathogenic
0.49
D
MetaRNN
Pathogenic
0.84
D;D;D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Uncertain
2.2
M;.;.;.;.;.
MutationTaster
Benign
1.0
D
PrimateAI
Uncertain
0.60
T
PROVEAN
Uncertain
-3.0
D;.;.;.;.;.
REVEL
Pathogenic
0.81
Sift
Pathogenic
0.0
D;.;.;.;.;.
Sift4G
Pathogenic
0.0
D;.;D;.;.;.
Polyphen
1.0
D;.;.;.;.;.
Vest4
0.76
MutPred
0.55
Gain of sheet (P = 0.0827);.;.;.;.;.;
MVP
1.0
MPC
1.1
ClinPred
0.79
D
GERP RS
4.7
gMVP
0.86

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: rs772620616; hg19: chr6-145948586; API