Mutations in the CHRNA7 gene in a family with Juvenile Myoclonic Epilepsy

RAUSCHEMBERGER, M. B.; VECCHI, C.; BARRANTES, F. J.

San Carlos de Bariloche, 17 al 21 de Noviembre de 2003

Congreso; XXXIX Congreso Sociedad Argentina de Bioquímica y Biología Molecular (SAIB); 2003

Sociedad Argentina de Investigación Básica (SAIB)

Juvenile Myoclonic Epilepsy (JME) is an idiopathic generalized epilepsy that affects up to 26% of all individuals with idiophatic generalized epilepsy . Approximately a third of JME patients have a positiv family history  of epilepsy. Strong evidence for linkage was foun to polymorphic loci encompassing the region containing the gene that encodes the neuronal AChR a7 subunit, wich maps to 15q14. Elmslie et al., (1997) suggested that this major locus  (EJM2) contributes to genetic susceptibility to JME in the majority of the families studied, but no precise localization was achieved. We studied a family with clinically diagnosed JME, and found a mutation at position 269 of the neuronal a7 AChR subunit. This corresponds to the M2 transmembrane segment, lining the walls of the AChR channel. The mutation consisted of the replacement of codon TTA by the codon ACA, resulting in the substitution Leu269Thr.