[1] It has features including intellectual disability, facial abnormalities, difficulty sleeping, and numerous behavioral problems such as self-harm.
These facial features become more noticeable as the individual ages, as mandible growth outstrips that of the maxilla leading to a clear midface hypoplasia.
Affected individuals 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.
Self-harm behaviours, including biting, hitting, head banging, and skin picking, are very common.
[citation needed] Other symptoms can include short stature, abnormal curvature of the spine (scoliosis), reduced sensitivity to pain and temperature, and a hoarse voice.
RAI1 is a transcription factor that regulates the expression of multiple genes, including several that are involved in controlling circadian rhythm, such as CLOCK.
[9] The groups led by James Lupski (Baylor College of Medicine) and Sarah Elsea (Virginia Commonwealth University) are in the process of studying the exact function of this gene in relation to Smith-Magenis syndrome.
This condition usually results from a genetic change that occurs during the formation of reproductive cells (eggs or sperm) or in early fetal development.
The characteristic micro-deletion was sometimes overlooked in a standard FISH test, leading to a number of people with the symptoms of SMS with negative results.