NM_005670.4:c.994_*12delTAGCTGGTCAGCCTG

Variant names:

• chr6-145627403-GCAGGCTGACCAGCTA-G
• NM_005670.4:c.994_*12delTAGCTGGTCAGCCTG

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_005670.4(EPM2A):​c.994_*12delTAGCTGGTCAGCCTG​(p.Ter332del) variant causes a stop lost, conservative inframe deletion change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: EPM2A NM_005670.4 stop_lost, conservative_inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.18

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Stoplost variant. No alternative stopcodon identified downstream, so we assume a Nonstop Mediated Decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
EPM2A	NM_005670.4	c.994_*12delTAGCTGGTCAGCCTG	p.Ter332del	stop_lost, conservative_inframe_deletion	Exon 4 of 4	ENST00000367519.9	NP_005661.1
EPM2A	NM_005670.4	c.995_*12delTAGCTGGTCAGCCTG		3_prime_UTR_variant	Exon 4 of 4	ENST00000367519.9	NP_005661.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
EPM2A	ENST00000367519.9	c.994_*12delTAGCTGGTCAGCCTG	p.Ter332del	stop_lost, conservative_inframe_deletion	Exon 4 of 4	1	NM_005670.4	ENSP00000356489.3
EPM2A	ENST00000367519	c.995_*12delTAGCTGGTCAGCCTG		3_prime_UTR_variant	Exon 4 of 4	1	NM_005670.4	ENSP00000356489.3

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Progressive myoclonic epilepsy Uncertain:1

May 04, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change disrupts the translational stop signal of the EPM2A mRNA. It is expected to extend the length of the EPM2A protein by 17 additional amino acid residues. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with EPM2A-related conditions. 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

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr6-145948539;