Clinical report: a male with Down syndrome, fragile X syndrome, and autism.

A case of a 14-year-old boy with both fragile X syndrome and Down syndrome is described. This is the third reported case of a patient with fragile X syndrome plus Down syndrome and the first reported case in a male. Facial features are generally consistent with Down syndrome; however, a prominent forehead and jaw and maccroorchidism were consistent with fragile X syndrome. Joint laxity is also present, which is consistent with both disorders. Cognitive impairment is more significant than in his siblings with fragile X syndrome, and he meets criteria for autistic disorder. Ongoing behavioral dysregulation has been significant, leading to disruption of home and school environments despite many attempted psychopharmacologic and behavioral strategies and a supportive family. Identification and treatment of underlying medical problems (esophagitis) led to improvements in sleep and behavior. We emphasize discussion of challenges in his behavioral management and present a collaborative approach to behavioral management.