STXBP1 and autism: These data place TBC1D24 alongside other more established synaptic proteins that are mutated in genetic forms of epilepsy but also play key roles in pathways essential for neurotransmission and synaptic homeostasis; for example, loss-of-function mutations in STXBP1 and SYN1 cause seizures and neurodevelopmental delay including autism in some SYN1 cases (4,6,36), and mutations in STX1B are associated with febrile epilepsy syndrome and myoclonic epilepsy (7,8).