ZDHHC9 and syndromic X-linked intellectual disability Raymond type: Hence, the ZDHHC9 gene is frequently associated with a syndromic condition called “Raymond-type X-linked syndromic intellectual developmental disorder (MRXSR, OMIM: 300,799)” that is characterized by mild to severe intellectual disability, speech and language difficulties, and additional variable features including marfanoid habitus, epilepsy, facial dysmorphism, hypotonia, and behavioral problems.