Smith-Magenis Syndrome

Developmental Disorder/Genetic Disorder

In The US: 1 in 15,000.

Genetics Home Reference




Smith-Magenis Syndrome is a developmental disorder created by the deletion of genetic material in the 17th chromosome. Features of the syndrome can include sleep disturbances where they feel exhausted during the day, but have problems falling and staying asleep. The syndrome also typically includes scoliosis, reduced sensitivity to pain and temperature, ear and eye abnormalities, and most significantly, mild to moderate mental disability. Mental impairment encompasses an additional range of problems like behavioral issues and delayed speech and language skills. Though it is uncommon, some people with Smith-Magenis Syndrome have also been reported to have heart and kidney defects.

Though the facial features associated with Smith-Magenis Syndrome are subtle in early childhood, they become more prominent with age. Most people with SMS have a broad, square-shaped face with deep-set eyes, full cheeks, and a prominent lower jaw. The middle of the face and the bridge of the nose often appear flattened and the mouth tends to turn downward. Those affected often have dental abnormalities as well.

People with Smith-Magenis Syndrome are typically very affectionate and engaging, but frequently experience behavior problems. This includes temper tantrums, angry outbursts, aggression, anxiety, self-injury, compulsive behavior, and problems paying attention. Repetitive self-hugging is also a trait that may be unique to this syndrome. With support, people with Smith-Magenis Syndrome can live a full, fulfilling life.

Smith-Magenis Syndrome In The News

Study Pins Down Biological Basis of Rare Autism-Linked Syndrome

Read More    published: 10/27/2016

Smith-Magenis Syndrome Research Foundation Ups Commitment to Dedicated Baylor Research Center

Read More    published: 03/01/2015

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