Smith-Magenis Syndrome: Clues in the Clinic.

As a multisystemic congenital mental retardation disorder/anomaly, Smith-Magenis syndrome (SMS) is commonly aroused from de novo interstitial deletion of the 17p11.2 chromosome. The deletion of this chromosome results with haploinsufficiency for the retinoic acid-induced 1 ( ) gene. In this article, we present three cases, who were diagnosed with SMS with mental retardation and behavioral problems such as self-hugging and sleeping disturbances. During the evaluation of the patients, it has been found that there was a 3.4-Mb deletion in the 17p11.2 chromosome region of these patients. This deletion includes that is a critically involved gene in SMS.