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Genetic and Rare Diseases Information Center (GARD)

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Smith-Magenis syndrome

Other Names for this Disease
  • Chromosome 17p11.2 deletion syndrome
  • SMS
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Is Smith-Magenis syndrome inherited?

Smith-Magenis syndrome is not typically inherited. The condition usually results from a genetic change that occurs during the formation of reproductive cells (eggs or sperm) or in early fetal development. Most often, people with Smith-Magenis syndrome have no history of the condition in their family.[1][2] In a very small number of cases, parental mosaicism has been reported. Complex familial chromosomal rearrangements leading to deletion of chromosome 17p11.2 and Smith-Magenis syndrome have also been reported. Again, these are very rare. As a result, chromosome analysis of the parents is suggested for all newly diagnosed individuals. This information can help to identify specific risks to other family members. For instance, if a parent of an individual with Smith-Magenis syndrome has a balanced chromosome rearrangement, at-risk family members (siblings, etc.) can be tested by chromosome analysis and FISH.[2]
Last updated: 2/15/2012

  1. Smith-Magenis syndrome. Genetics Home Reference (GHR). 2007; Accessed 2/15/2012.
  2. Smith ACM et al.. Smith-Magenis Syndrome - Genetic Counseling. GeneReviews. January 7, 2010; Accessed 2/15/2012.