Smith–Magenis syndrome

Smith–Magenis Syndrome (SMS) has features including intellectual disability, facial abnormalities, difficulty sleeping, and numerous behavioral problems such as self-harm. Smith–Magenis syndrome affects an estimated between 1 in 15,000 to 1 in 25,000 individuals. Smith–Magenis Syndrome (SMS) has features including intellectual disability, facial abnormalities, difficulty sleeping, and numerous behavioral problems such as self-harm. Smith–Magenis syndrome affects an estimated between 1 in 15,000 to 1 in 25,000 individuals. It is a microdeletion syndrome characterized by an abnormality in the short (p) arm of chromosome 17 and is sometimes called the 13p- syndrome. Facial features of children with Smith–Magenis syndrome include a broad and square face, deep-set eyes, large cheeks, and a prominent jaw, as well as a flat nose bridge (in the young child; as the child ages it becomes more ski-jump shaped). Eyes tend to be deep-set and appear close together there is also a slant upwards. Eyebrows are heavy with lateral extension. The mouth is the most noticeable feature, both upper and lower lips are full, the mouth is wide. The mouth curves downwards and the upper lip curves outwards, due to a fleshy philtrum. These facial features become more noticeable as the individual ages, as Mandible growth outstrips that of the maxilla leading to a clear midface hypoplasia. There is also a mild brachycephaly. Disrupted sleep patterns are characteristic of Smith–Magenis syndrome, typically beginning early in life. Affected people may be very sleepy during the day, but have trouble falling asleep and awaken several times each night, due to an inverted circadian rhythm of melatonin.