New variants in the CACNA1H gene identified in childhood absence epilepsy

Childhood absence epilepsy (CAE) is a common form of idiopathic generalized epilepsy with polygenic inheritance. In our previous studies, relatively high frequent variants in the T-type calcium channel gene, CACNA1H, were identified in the Chinese Han population, most of which are located in exons 6-12. The goal of this study was to identify additional variants in this region of the CACNA1H gene. To this end, exons 6-12 were sequenced in 100 newly recruited CAE trios and 191 normal controls. Thirty-nine variants were identified in CAE trios or controls, 14 of which were found only in CAE patients, including two nonsynonymous variants that were newly found. Thirteen of the 39 variants were found in both CAE patients and controls, 11 were found only in parents of CAE trios, and one was found only in controls. Twenty-eight of these variants had not been previously reported. Both permutation test and transmission/disequilibrium test (TDT) indicated that a SNP-52037C>T in intron11 was significant in association with CAE. In conclusion, these data further support the hypothesis that CACNA1H is an important susceptibility gene for CAE in the Chinese Han population.