6-145627437-A-C

Variant names:

• chr6-145627437-A-C
• NM_005670.4:c.975T>G
• EPM2A p.Arg325Arg

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_005670.4(EPM2A):​c.975T>G​(p.Arg325Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. R325R) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: EPM2A NM_005670.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.265
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• Lafora disease

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.82).
• BP7: Synonymous conserved (PhyloP=0.265 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005670.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	EPM2A	NM_005670.4	MANE Select	c.975T>G	p.Arg325Arg	synonymous	Exon 4 of 4	NP_005661.1	O95278-1
	EPM2A	NM_001360064.2		c.561T>G	p.Arg187Arg	synonymous	Exon 4 of 4	NP_001346993.1	O95278-8
	EPM2A	NM_001360071.2		c.561T>G	p.Arg187Arg	synonymous	Exon 5 of 5	NP_001347000.1	O95278-8

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	EPM2A	ENST00000367519.9	TSL:1 MANE Select	c.975T>G	p.Arg325Arg	synonymous	Exon 4 of 4	ENSP00000356489.3	O95278-1
	EPM2A	ENST00000639423.1	TSL:1	c.561T>G	p.Arg187Arg	synonymous	Exon 4 of 4	ENSP00000492701.1	O95278-8
	EPM2A	ENST00000638262.1	TSL:1	c.*58T>G		3_prime_UTR	Exon 3 of 3	ENSP00000492876.1	O95278-5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
CADD	Benign	1.4
DANN	Benign	0.43
PhyloP100		0.27

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr6-145948573;