Pedigree analysis of idiopathic epilepsy in children of South Kerala

Abstract

Background and aims: Epilepsy is a major health problem in infancy and childhood. Genetic factors are implicated in the etiology of epilepsy. A familial susceptibility to seizures have been recognized but the exact mode of inheritance remains unclear. The chief objective was to determine the inheritance pattern and to correlate its prevalence among closer relatives on the basis of sex, degree of relationship and age of onset of the disease. Materials and methods: A pedigree analysis of 100 clinically diagnosed children with idiopathic epilepsy seen between 1994 and 1997 at the Paediatric Neurology Clinic of Government Medical College, Thiruvananthapuram was done. The mode of inheritance was tested according to the genetic hypothesis of segregation analysis. Results: Positive family history was observed in 49% of the probands. A high proportion of probands with an early onset of disease showed involvement of family members and a significant sex predisposition for females was obtained. Relatives of female probands were affected more than those of males. Mothers were found to transmit the disease to offsprings more than the epileptic fathers. Conclusion: The results of pedigree analysis supported the hypothesis of an autosomal multifactorial mode of inheritance, with 86% heritability and a lower threshold for the disease to manifest. The application of modern genetic principles like identification of susceptibility gene to epilepsy, linkage and association studies would advance our understanding of the etiology of seizure disorders. Genetic factors may play a major role in the predisposition of relatives to epilepsy in families of probands with idiopathic epilepsy. The present study may aid in the genetic counselling of parents with epilepsy