Isolation and characterization of mouse homologue for the human epilepsy gene, EPM2A.

Mutations in the novel gene, EPM2A, have been shown recently to cause the progressive myoclonus epilepsy of Lafora type. EPM2A is predicted to encode a putative protein-tyrosine phosphatase but its specific role in normal brain function and in the Lafora disease is not known. As a first step towards understanding the cellular function of EPM2A in an animal model, we have isolated cDNA clones for mouse EPM2A and analyzed its expression. Sequence analyses of the mouse cDNA clones revealed a complete ORF that supports the 5' coding sequence predicted for human EPM2A from the genomic sequence. When compared to EPM2A, the mouse homologue, named Epm2a, shows 86% identity at the nucleotide level and 88% identity and 93% similarity at the amino acid level. Similar to the human counterpart, Epm2a showed ubiquitous expression in Northern with a major transcript size of 3.5 kb. We have mapped the Epm2a to the proximal region of mouse chromosome 10 which is the syntenic region for human chromosome band, 6q24. Our results suggest that EPM2A is highly conserved in mammals and might have a conserved function.