Functional Analysis of Cav3.2 T-type Calcium Channel Mutations Linked to Childhood Absence Epilepsy.
Peloquin, Jean B. *; Khosravani, Houman *; Barr, Wendy *,++; Bladen, Chris *,++; Evans, Rhian *; Mezeyova, Janette +; Parker, David +; Snutch, Terrance P. +; McRory, John E. *; Zamponi, Gerald W. *
[Letter] Epilepsia. 47(3):655-658, March 2006.

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Purpose: Childhood absence epilepsy (CAE) is an idiopathic form of seizure disorder that is believed to have a genetic basis.

Methods: We examined the biophysical consequences of seven mutations in the Cav3.2 T-type calcium channel gene linked to CAE.

Results: Of the channel variants examined, one of the mutants, a replacement of glycine 848 in the domain II-S2 region with serine, resulted in significant slowing of the time courses of both activation and inactivation across a wide range of membrane potentials. These changes are consistent with increased channel activity in response to prolonged membrane depolarizations.

Conclusions: Taken together, these findings suggest that such little changes in channel gating may contribute to the etiology of CAE.

(C) International League Against Epilepsy