Multiple genetic factors were identified to be involved in primary epilepsy syndromes for which epileptic seizures are the predominant clinical feature; the same hold true in brain developmental disorders for which epileptic seizures are secondary clinical features. Recent whole-exome sequencing (WES) data suggest that mutations causing epileptic encephalopathies are often sporadic. These mutations are typically de novo dominant variations that affect a single autosomal gene but autosomal recessive and X-linked inheritance were also reported .