An inherited nonsense R1645X mutation in neuronal sodium channel alpha1-subunit gene in a Turkish patient with severe myoclonic epilepsy of infancy.

Severe myoclonic epilepsy of infancy (SMEI) is a well-known catastrophic epileptic syndrome. Several mutations of the sodium channel alpha 1 subunit (SCN1A ) gene were reported in patients with SMEI. Most of the mutations were DE NOVO. Inherited truncating mutations are very rare. Here a patient with a new nonsense mutation (c.4933 C>T; p.R1645X) of the gene is described. This mutation was inherited from the father who had only febrile seizures during childhood. (c) Georg Thieme Verlag KG Stuttgart, New York.