Genetics

Genetics of Smith-Magenis Syndrome

Smith-Magenis syndrome (SMS) was first associated with a de novo deletion on chromosome 17p11.2. De novo refers to a new genetic change that occurs spontaneously and is not inherited from either parent.

More recently, some individuals with features of SMS have been found to have changes to the retinoic acid-induced 1 (RAI1) gene, which is also located on chromosome 17p11.2. This discovery has led researchers to conclude that the RAI1 gene is responsible for most of the key features of the syndrome. While most SMS cases (around 80-90%) are caused by the chromosome 17p11.2 deletion, changes to the RAI1 gene account for approximately 10-20% of cases. In a very small percentage of cases, the features of SMS are not linked to either chromosome 17p11.2 deletion or changes to the RAI1 gene.

For more information on the genetics of Smith-Magenis syndrome, you can visit the Smith-Magenis Syndrome Foundation website.

Visit the Smith-Magenis Syndrome Foundation page to read more about genetics.