Smith-Magenis syndrome (SMS; OMIM #182290) occurs when there is not enough functional RAI1 present. This can occur when there is a chromosome 17p11.2 deletion that includes RAI1or when there is an error in the sequence of the RAI1gene that makes RAI1 non-functional.
SMS Is a disorder that will impact multiple developmental milestones, resulting in speech and motor delays, distinct facial differences, learning difficulties, aggressive and self-harming behaviors, differences in sleep schedule with reduced nighttime sleep, and overweight/obesity with age. SMS typically does not run in families but can be passed from a parent to a child. SMS occurs in about 1 out of 25,000 live births.