Meta-analysis of the frequency of Febrile Seizures and Epilepsy in first degree relatives of patients with Dravet Syndrome and mutations in SCN1A. Studies were subdivided into studies reporting the frequency in first degree relatives vs. all relatives. In summary, the current data suggests a frequency of Febrile Seizures or Epilepsy in 10-15% of patients with Dravet Syndrome, a finding suggestive of familial aggregation when compared to an estimated population frequency of 5% or lower. However, few studies have included control data.