Smith-Magenis Syndrome

**Definition:** Complex neurobehavioral disorder characterized by distinctive facial features (FACIES), developmental delay and INTELLECTUAL DISABILITY. Behavioral phenotypes include sleep disturbance, maladaptive, self-injurious and attention-seeking behaviors. The sleep disturbance is linked to an abnormal circadian secretion pattern of MELATONIN. The syndrome is associated with de novo deletion or mutation and HAPLOINSUFFICIENCY of the retinoic acid-induced 1 protein on chromosome 17p11.2.

**Tree numbers:** - C10.281.900 - C16.131.077.879 - C16.131.260.887 - C16.320.180.887

**Synonyms:** - Chromosome 17p11.2 Deletion Syndrome