Genetic influence on the clinical characteristics and outcome of febrile seizures--a retrospective study.

PURPOSE: To assess the influence of the family history (FH) of epilepsy or febrile seizures (FSs) on the clinical presentation of FSs and on their outcome. METHODS: We reviewed the charts of 482 children admitted to the Ste-Justine Hospital with FSs between 3 months and 6 years of age and followed for at least 5 years. RESULTS: Children with a positive FH of epilepsy (n=67) showed significantly more focal and recurrent FSs than those without such a FH. The risk of developing partial epilepsy (n=17) or generalized epilepsy (n=19) was significantly greater in children with focal or recurrent FSs, respectively. In children with focal FSs, only two out of 30 (6.7%) children with a negative FH of epilepsy developed partial epilepsy compared with four out of nine (44.4%) children with a positive FH. In children with recurrent FSs, as much as seven out of 34 (20.6%) children with a positive FH of epilepsy developed generalized epilepsy compared to only eight out of 161 (0.05%) of those with a negative FH. Nevertheless, when not taking into account the clinical presentation of FSs, the positive FH of epilepsy constituted a risk factor for developing generalized but not partial epilepsy. Finally, children with a positive FH of FSs (n=120) exhibited significantly more recurrent FSs than those without such a FH, but this did not modify the risk of epilepsy. CONCLUSION: The FH of FSs and/or epilepsy should be taken into account when evaluating the risk of FSs recurrence and of epilepsy.