1. ¹Department of Pediatrics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA
2. ²Department Human Genetics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA

Correspondence: Dr SH Elsea, Department of Pediatrics, Medical College of Virginia Campus, Virginia Commonwealth University, 12-018 Sanger Hall, 1101 E Marshall Street, PO Box 980441, Richmond, VA 23298, USA. Tel: 804 628 0987; Fax: 804 628 1609; E-mail: selsea@vcu.edu

Received 18 July 2007; Revised 15 November 2007; Accepted 16 November 2007; Published online 30 January 2008.

Abstract

Smith–Magenis syndrome (SMS) is a complex neurobehavioral disorder caused by haploinsufficiency of the retinoic acid-induced 1 (RAI1) gene on chromosome 17p11.2. Diagnostic strategies include molecular identification of a 17p11.2 microdeletion encompassing RAI1 or a mutation in RAI1. G-banding and fluorescent in situ hybridization (FISH) are the classical methods used to detect the SMS deletions, while multiplex ligation-dependent probe amplification (MLPA) and real-time quantitative PCR are the newer, cost-effective, and high-throughput technologies. Most SMS features are due to RAI1 haploinsufficiency, while the variability and severity of the disorder are modified by other genes in the 17p11.2 region. The functional role for RAI1 is not completely understood, but it is likely involved in transcription, based on homology and preliminary studies. Management of SMS is primarily a multidisciplinary approach and involves treatment for sleep disturbance, speech and occupational therapies, minor medical interventions, and management of behaviors.