Benign Familial Infantile Convulsions: Phenotypic Variability in a Family

Abstract

Benign familial infantile convulsion is an autosomal dominant epilepsy syndrome characterized by seizures starting from 3 to 12 months and a favorable outcome. We present a Turkish family with benign familial infantile convulsions and report the clinical variability associated with this syndrome in three generations. All 11 affected members had benign infantile seizures, which were primarily generalized in all but one patient, who had partial seizures with secondary generalization. The seizures started within the first year and were accompanied by normal neurologic development and a good response to treatment with phenobarbital. In this family, the phenotype extended beyond infancy. The index patient had unilateral occipital spike and waves on electroencephalography (EEG), although he had no clinical seizures at 4 years of age. Follow-up EEG of this patient 1 year later showed that the discharges shifted to the occipital lobe of the other hemisphere. The grandmother of this patient had temporal lobe seizures as an adult, years after the remission of infantile convulsions. One of the patients experienced paroxysmal choreoathetosis during adolesence. Our findings highlight the intrafamilial phenotypic variability of benign familial infantile convulsions in a large pedigree with long-term follow-up.