In the context of other specific gene syndromic autism, our findings of a male bias in NF1-ASD are similar to results in SHANK1 [15] and Down’s syndrome [16]; however, this sex disparity is not seen in genetic disorders associated with high levels of intellectual impairment, such as tuberous sclerosis [34] and Cornelia de Lange syndrome [35]. Here, NF1 is linked to Down syndrome.