Even though most ASDs occur sporadically;, some are genetic-

1. Holt-Oram syndrome (mutations in TBX5, a member of the Brachyury (T) gene family).

2. Mutations in NKX2.5 and GATA4.

3. Missense mutation in myosin heavy chain 6 (chro 14q12)- causes familial ASD.