title: Functional analysis of Ca3.2 T-type calcium channel mutations linked to childhood absence epilepsy.
abstract: OBJECTIVE
  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 Ca(v)3.2 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.
authors.affiliation: Department of Physiology and Biophysics, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta.
authors.forename: Jean B
authors.initials: JB
authors.lastname: Peloquin
authors.forename: Houman
authors.initials: H
authors.lastname: Khosravani
authors.forename: Wendy
authors.initials: W
authors.lastname: Barr
authors.forename: Chris
authors.initials: C
authors.lastname: Bladen
authors.forename: Rhian
authors.initials: R
authors.lastname: Evans
authors.forename: Janette
authors.initials: J
authors.lastname: Mezeyova
authors.forename: David
authors.initials: D
authors.lastname: Parker
authors.forename: Terrance P
authors.initials: TP
authors.lastname: Snutch
authors.forename: John E
authors.initials: JE
authors.lastname: McRory
authors.forename: Gerald W
authors.initials: GW
authors.lastname: Zamponi
mesh_terms: D000818:Animals; D020747:Calcium Channels, T-Type / Q000235:genetics* / Q000502:physiology; D002478:Cells, Cultured; D002648:Child; D004832:Epilepsy, Absence / Q000235:genetics* / Q000503:physiopathology; D005998:Glycine / Q000235:genetics / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D015640:Ion Channel Gating / Q000235:genetics / Q000502:physiology; D008564:Membrane Potentials / Q000235:genetics; D009154:Mutation / Q000235:genetics* / Q000502:physiology; D020125:Mutation, Missense / Q000235:genetics / Q000502:physiology; D051381:Rats; D012694:Serine / Q000235:genetics
chemical_list: D020747:Calcium Channels, T-Type; D012694:Serine; D005998:Glycine