By screening a cohort of ASD individuals affected by ASD and/or epilepsy for SYN genes other than SYN1, we have identified several rare variants in SYN2, namely one nonsense (n = 1) and two missense (n = 2) mutations in ASD patients and one missense (n = 1) mutation in an epileptic patient. The gene discussed is SYN2; the disease is epilepsy.