Numerous associations between epilepsy and autism have been linked to numerous types of gene mutations, such as genetic syndromes (like maternally inherited chromosome 15q11-q13 syndrome, Down syndrome, Phelan-McDermid syndrome) or single gene disorders (like Fragile X Syndrome, Tuberous Sclerosis Complex, MECP-2-related syndrome) [15,16]. The gene discussed is MECP2; the disease is fragile X syndrome.