Objective: Childhood absence epilepsy (CAE) is one of the most frequently recognized syndromes among the idiopathic generalized epilepsies (IGEs). It is considered to be a hereditary disease. The possible inheritance pattern of CAE is polygenic. The genes responsible for CAE, however, have not yet been identified. The aim of this study was to further investigate based on the authors' recent work whether or not T-type calcium channel gene-CACNA1H is a susceptibility gene to childhood absence epilepsy.
Methods: The authors conducted the mutation screening of the exons 6-12 and the nearby partial introns of the CACNA1H gene using the method of direct sequencing of PCR products in 48 newly found CAE patients.
Results: The authors found 13 single nucleotide polymorphisms (SNPs). They also found 4 mutations which only existed in CAE patients. Both G773D and H515Y mutations were heterozygous. The mutation of H515Y has never been reported previously. The patient inherited the mutation from his mother. The authors found two CAE patients with the mutation of G773D previously. This is the third time that the authors found one more CAE family with this G773D mutation, and the patient with the mutation G773D inherited the mutation from his father.
Conclusion: T-type calcium channel gene-CACNA1H might be a susceptibility gene to childhood absence epilepsy.