We appreciate the insightful comments of Dr Chaudhury and the opportunity to extend the discussion of our study. We agree that in addition to achalasia most of the phenotypes presented by these children could be attributed to the nNOS mutation. Nitric oxide is proposed to play a role in the pathogenesis of autism.1 In Fragile X syndrome, the leading monogenic cause of intellectual disability and autism, loss of function of the RNA-binding protein FMRP2 results in decreased nNOS translation in the developing human brain.