Familial occurrence of epilepsy in children with newly diagnosed multiple seizures: Dutch study of epilepsy in childhood

Purpose: To study the familial occurrence of epilepsy in children with newly diagnosed multiple unprovoked seizures. Methods: Between August 1988 and September 1992, 462 children with two or more unprovoked seizures were included in the prospective Dutch Study of Epilepsy in Childhood. Seizures and epilepsy syndromes of probands were classified according to the International Classifications. Probands with at least 1 first-degree relative with epilepsy were selected. Seizures and syndromes of their relatives were classified using medical files and telephone interviews. Results: In 42% of the probands, the epilepsy was classified as localization-related, in 57% as generalized, and in 1% as undetermined whether focal or generalized. The 47 (10.2%) children with at least 1 first-degree relative with epilepsy less frequently had localization-related epilepsy (23%) and more often had generalized epilepsy (77%) as compared with the total group Of probands. Fifty-eight first-degree and 21 other relatives had epilepsy. Thirty-three of the 40 (83%) first-degree relatives with idiopathic or cryptogenic epilepsy had the same seizure type as the proband, but detailed information about their seizures was sometimes difficult to obtain. Of the 12 first-degree relatives with epilepsy syndromes classifiable according to the International League Against Epilepsy (ILAE) 7 (58%) had the same syndrome as the proband. Conclusions: In 10% of children with newly diagnosed epilepsy, the condition is familial. Relatively more often, these children have generalized epilepsy syndromes as compared with children with a negative family history. Most of the relatives with idiopathic or cryptogenic epilepsy had the same seizure type as the proband. These findings confirm the role of genetic factors in the pathogenesis of epilepsy.