What is Smith Magenis syndrome?
Smith Magenis syndrome (SMS) is a genetic disorder that affects many parts of a person’s body. It is caused by missing information in a gene called RAI1. The main symptoms of Smith Magenis syndrome are:
- Developmental delay (especially in speech and language)
- Intellectual disabilities
- Problems with sleep
- Behavior problems
- Unique facial features
Their faces are often square shaped with a large jaw. The middle of the face is flat. Sleep problems usually begin during childhood and include problems falling asleep at night and being very tired during the day. Behavior problems can include severe temper tantrums, aggression, anxiety, difficulty paying attention, and difficulty learning. Injuring themselves is common in children with SMS. A unique symptom that is not seen in many other genetic disorders is called "lick and flip". This means that individuals lick their fingers and turn the pages of magazines or books over and over again. Other symptoms may include short height, vision problems,hearing problems, and occasionally heart and kidney problems. The type of doctor that usually diagnoses SMS is a medical geneticist. They can help coordinate care. To find a genetics clinic near you, visit the Genetic Services Search Engine on the American College of Medical Genetics website.
- Smith ACM, Boyd KE, Elsea SH, et al. Smith-Magenis Syndrome. 2001 Oct 22 [Updated 2012 Jun 28]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2016.
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Are there other names for Smith Magenis syndrome?
Other names for Smith Magenis syndrome include:
- Chromosome 17p11.2 Deletion Syndrome
- Smith-Magenis Chromosome Region (SMCR)
- Chromosome 17, interstitial deletion 17p
The type of doctor that usually diagnoses SMS is a medical geneticist. They can help coordinate care. To find a genetics clinic near you, visit the Genetic Services Search Engine on the American College of Medical Genetics website.
How common is Smith Magenis syndrome?
Smith Magenis syndrome (SMS) occurs in at least 1 in 25,000 individuals. However, researchers think that some people may go through their whole life and never be diagnosed, meaning that this disorder may be more common than is currently realized.
- Smith Magenis Syndrome. (2013). U.S. National Library of Medicine. http://ghr.nlm.nih.gov/condition/smith-magenis-syndrome
- Greenberg F., Guzzetta V., Montes de Oca-Luna R., et al. Molecular analysis of the Smith-Magenis syndrome: a possible contiguous-gene syndrome associated with del(17)(p11.2). Am J Hum Genet. 1991;49:1207-18. http://www.ncbi.nlm.nih.gov/pubmed/8882782
What is the usual abbreviation for Smith Magenis syndrome?
SMS is the usual abbreviation for Smith Magenis syndrome.