摘要：

Recently, genetic causes have been identified in severe myoclonic epilepsy in infancy and certain epilepsy syndromes in which the phenotypes are similar to common idiopathic epilepsies. Interestingly, almost all such genetic abnormalities were detected in genes encoding ion channels expressed in the brain. Such channels include GABAA receptor and K+ channels each of which plays an important role in the neuronal inhibitory system. Mutations of the genes encoding several subunits of GABAA receptor, a ligand-gated ion channel, were identified as underlying causes of various epilepsy syndromes: A missense mutation of the gene encoding α 1 subunit of the receptor, GABRA1 was found to be associated with autosomal dominant juvenile myoclonic epilepsy and several missense mutations of γ 2 were found in febrile seizure related epilepsy syndromes such as autosomal dominant epilepsy with febrile seizures plus or generalized epilepsy with febrile seizures plus. Mutations within the same gene can result in different epilepsy phenotypes. Abnormality of γ 2 subunit of GABAA receptor may be also associated with severe myoclonic epilepsy in infancy. Mutations of two KCNQ K+ -channel genes, KCNQ2 and KCNQ3, were identified in benign familial neonatal convulsions. Mutation of another K+ -channel gene, KCNA1, can cause episodic ataxia type 1 and epilepsy.

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