Frequent mutations of SCN1A in severe myoclonic epilepsy in infancy

Mutations in the neuronal voltage-gated sodium channel alpha-subunit type I gene (SCN1A) were found responsible for severe myoclonic epilepsy in infancy (SMEI). The authors describe novel mutations of SCN1A in Japanese patients with SMEI. They screened 12 unrelated patients and a pair of monozygotic twins and detected 10 mutations that lead to truncation of the protein.