Myoclonic Epilepsy, Juvenile, Susceptibility To, 4

For a phenotypic description and a discussion of genetic heterogeneity of juvenile myoclonic epilepsy (JME), see 254770. JME is a form of idiopathic generalized epilepsy (IGE; 600669).

Clinical Features

Kapoor et al. (2007) reported a family from southern India in which 8 individuals had juvenile myoclonic epilepsy inherited in an autosomal dominant pattern. The proband was a 32-year-old woman who developed morning myoclonic jerks at age 14 years and generalized tonic-clonic seizures at age 20. EEG recordings showed polyspike and wave discharges characteristic of a generalized epilepsy. Other affected members had a similar history. None had absence or febrile seizures. Response to medication was good.

Mapping

By genomewide linkage analysis of an Indian family with juvenile myoclonic seizures, Kapoor et al. (2007) identified a candidate locus, referred to here as EJM4, on chromosome 5q12-q14 (2-point lod score of 3.33 at D5S459; parametric multipoint lod score of 3.33 at D5S641 and D5S459). Haplotype analysis delineated a 25-Mb region between D5S624 and D5S428.