SYNGAP1 and Lissencephaly: However, positive outcomes have also been observed in Sturge–Weber syndrome, focal cortical dysplasia, lissencephaly, brain tumor-related epilepsy, frontal and temporal lobe epilepsy, and some rare forms of epilepsy, including CDKL5 deficiency disorder, SYNGAP1 encephalopathy, epilepsy with myoclonic absences, as well as Aicardi, Dup15q, and Doose syndromes.