Genetic association analysis of KCNQ3 and juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) is a common subtype of idiopathic generalized epilepsy that shows a complex pattern of inheritance. We have tested the associ- ation between JME phenotype and an intragenic marker in KCNQ3 by using the transmission disequilibrium test in 119 probands and their parents. Mutations in KCNQ3 are known to cause benign familial neonatal convulsions and are involved in the physiologically important M current in neurons. Our results provide suggestive evidence of allelic association between JME and KCNQ3 (P-value=0.008) and raise an interesting possibility of a genetic contribu- tion to JME, viz., of a gene that causes a monogenic form of human epilepsy. Juvenile myoclonic epilepsy (JME, OMIM 606904) is a common subtype of idiopathic generalized epilepsy (IGE). It accounts for about 8% of all epilepsies in South India (Murthy et al. 1998). A major genetic component in etiol- ogy of JME is well established (Obeid and Panayiotopou- los 1988). Many of the 40 or so genes identified so far as causing idiopathic epilepsies are molecular components