Familial aggregation of status epilepticus in generalized and focal epilepsies

Objective To determine whether familial aggregation of status epilepticus (SE) occurs in a large cohort of familial common epilepsies. Methods We used the Epilepsy Phenome/Genome Project dataset, which consisted of 2,197 participants in 1,043 family units with >= 2 members having a common generalized or nonacquired focal epilepsy (NAFE). We identified participants with a history of traditionally defined SE (TSE) (seizures >= 30 minutes) and operationally defined SE (OSE) (seizures =10 minutes) by chart review. We assessed familial aggregation of TSE and OSE using.2 analysis and generalized estimating equations (GEE). Results One hundred fifty-five (7%) participants in 1,043 families had >= 1 episodes of TSE. Two hundred fifty (11%) had >= 1 episodes of OSE. In a chi(2) analysis, the number of family units with >= 2 members having TSE (odds ratio [OR] 4.79, 95% confidence interval [CI] 2.56-8.97) or OSE (OR 4.23, 95% CI 2.67-6.70) was greater than expected by chance. In GEE models adjusted for sex, broad epilepsy class (GE or NAFE), age at onset, and duration of epilepsy, TSE in a proband predicted TSE in a first-degree relative (OR 2.79, 95% CI 1.24-6.22), and OSE in a proband predicted OSE in a first-degree relative (OR 2.91, 95% CI 1.65-5.15). The results remained significant in models addressing epilepsy severity by incorporating the number of antiseizure medications used or epilepsy surgery. Conclusions TSE and OSE showed robust familial aggregation in a cohort of familial epilepsy independently of epilepsy severity or class, suggesting that genetic factors contribute to SE independently of the genetic cause of these epilepsies.