ZDHHC9-associated neurodevelopmental disorder (also known as Raymond-type X-linked Intellectual Disability Syndrome, OMIM # 300799) is a rare X-linked neurodevelopmental syndrome. 7 families have been reported in the literature since the first cases in 2007, and the number of diagnoses worldwide is growing. It may be under-diagnosed, because of the relatively mild cognitive impairments and X-linked inheritance pattern.