GENETIC PREDISPOSITION TO WEST SYNDROME

To determine the recurrence risk of West syndrome (WS), we studied the familial antecedents of consecutively referred patients. Among siblin gs, there was an increased incidence of WS but not of febrile convulsi ons. Familial incidence of epilepsy was intermediate between the epile ptic and nonepileptic control groups. When cases resulting from a gene tically determined disease were excluded, incidence of epilepsy among siblings was similar to that in normal controls. Five of the 11 famili al cases of WS were due to an identifiable cause: twin pregnancy, tube rous sclerosis, and recurrent maternal toxemia. In 4 of the remaining families, the clinical picture included spasms, erratic myoclonus, and postnatal microcephaly, suggestive of a previously unidentifiable pro gressive encephalopathy. Therefore, when identifiable familial disease s were excluded, the recurrence risk was <1%.