Researchers at Women's And Children's Hospital, North Adelaide, and other centers in Australia and Canada screened 240 individuals from 167 families with idiopathic generalized epilepsy and generalized epilepsy with febrile seizures plus (GEFS+) and 95 controls for variants in the CACNA1H gene. They identified 19 novel variants causing amino acid changes associated with the following epilepsy syndromes: childhood absence epilepsy, juvenile absence, juvenile myoclonic, idiopathic generalized with tonic-clonic seizures, and temporal lobe epilepsy. The variants also occurred in unaffected individuals. In some families, the variant segregated with epilepsy, but not in others. It is concluded that variants in CACNA1H gene that alter channel properties occur in patients with various generalized epilepsy syndromes, contributing to epilepsy susceptibility but not sufficient to cause epilepsy themselves. 
COMMENT. Variants in the CACNA1H gene are associated with a range of generalized epilepsy syndromes, but additional genes or environmental factors also may influence epilepsy susceptibility in some individuals. These genetic variants can contribute to a risk of epilepsy but are not themselves the cause.