Résumé
<p><b>OBJECTIVE</b>To study the effect of CACNA1H gene mutation G773D on calcium channel function.</p><p><b>METHODS</b>By the overlap extension PCR we introduced G773D mutation into a human Cav3.2acDNA for constructing the mutant. And then using whole cell clamp technique, we studied the alterations of channel behavior in transfected HEK-293 cells.</p><p><b>RESULTS</b>There were no difference in kinetics of activation and inactivation of calcium channel between wild type and mutant. However comparing with the wild-type Cav3.2 channel, G773D mutant could increase the calcium current density significantly.</p><p><b>CONCLUSION</b>CACNA1H gene G773D mutation is able to increase calcium current and neuronal excitability.</p>
Sujets)
Enfant , Enfant d'âge préscolaire , Femelle , Humains , Mâle , Séquence nucléotidique , Canaux calciques de type T , Génétique , Physiologie , Lignée cellulaire , Analyse de mutations d'ADN , Petit mal épileptique , Génétique , Anatomopathologie , Santé de la famille , Données de séquences moléculaires , Mutation , Techniques de patch-clamp , Polymorphisme de nucléotide simpleRésumé
<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>T-type calcium channel gene-CACNA1H might be a susceptibility gene to childhood absence epilepsy.</p>