NM_005670.4:c.446T>C

Variant names:

• chr6-145686152-A-G
• rs796052430
• NM_005670.4:c.446T>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_005670.4(EPM2A):​c.446T>C​(p.Ile149Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,846 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. I149M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: EPM2A NM_005670.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 8.94
• 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: ClinGen, Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)

ENSG00000307801 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

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.446T>C	p.Ile149Thr	missense	Exon 2 of 4	NP_005661.1	O95278-1
	EPM2A	NM_001368129.2		c.-178T>C		5_prime_UTR_premature_start_codon_gain	Exon 2 of 5	NP_001355058.1	O95278-7
	EPM2A	NM_001368132.1		c.-178T>C		5_prime_UTR_premature_start_codon_gain	Exon 2 of 5	NP_001355061.1	O95278-7

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	EPM2A	ENST00000367519.9	TSL:1 MANE Select	c.446T>C	p.Ile149Thr	missense	Exon 2 of 4	ENSP00000356489.3	O95278-1
	EPM2A	ENST00000435470.2	TSL:1	c.446T>C	p.Ile149Thr	missense	Exon 2 of 5	ENSP00000405913.2	O95278-2
	EPM2A	ENST00000638262.1	TSL:1	c.446T>C	p.Ile149Thr	missense	Exon 2 of 3	ENSP00000492876.1	O95278-5

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152196 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

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

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251330 AF XY: 0.00000736

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461650 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727116

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.0000224 AC: 1 AN: 44662

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111876

Other (OTH) AF: 0.0000497 AC: 3 AN: 60390

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152196 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74342

African (AFR) AF: 0.00 AC: 0 AN: 41446

American (AMR) AF: 0.000196 AC: 3 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68030

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000936 Hom.: 0

Bravo AF: 0.0000416

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Inborn genetic diseases (1)
-	1	-	not provided (1)
-	1	-	Progressive myoclonic epilepsy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.16	T
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Benign	0.029	D
MetaRNN	Uncertain	0.71	D
MetaSVM	Benign	-0.78	T
MutationAssessor	Benign	1.5	L
PhyloP100		8.9
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-1.8	N
REVEL	Uncertain	0.32
Sift	Uncertain	0.012	D
Sift4G	Uncertain	0.0070	D
Polyphen		0.84	P
Vest4		0.83
MutPred		0.65		Loss of stability (P = 0.0406)
MVP		0.81
MPC		0.66
ClinPred		0.93	D
GERP RS		5.6
PromoterAI		0.027	Neutral
gMVP		0.71
Mutation Taster		=49/51	disease causing

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

Other links and lift over

dbSNP: rs796052430; hg19: chr6-146007288;