Smith–Magenis Syndrome: Clues in the Clinic
01 January 2019
22 November 2019
06 January 2020 (online)
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 (RAI1) 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 RAI1 that is a critically involved gene in SMS.
Informed consent form was received from the families of all the patients for the presentation of the case reports.
- 1 Smith AC, McGavran L, Robinson J. , et al. Interstitial deletion of (17)(p11.2p11.2) in nine patients. Am J Med Genet 1986; 24 (03) 393-414
- 2 Slager RE, Newton TL, Vlangos CN, Finucane B, Elsea SH. Mutations in RAI1 associated with Smith-Magenis syndrome. Nat Genet 2003; 33 (04) 466-468
- 3 Vlangos CN, Yim DK, Elsea SH. Refinement of the Smith-Magenis syndrome critical region to approximately 950kb and assessment of 17p11.2 deletions. Are all deletions created equally?. Mol Genet Metab 2003; 79 (02) 134-141
- 4 Elsea SH, Girirajan S. Smith-Magenis syndrome. Eur J Hum Genet 2008; 16 (04) 412-421
- 5 Juyal RC, Figuera LE, Hauge X. , et al. Molecular analyses of 17p11.2 deletions in 62 Smith-Magenis syndrome patients. Am J Hum Genet 1996; 58 (05) 998-1007
- 6 Edelman EA, Girirajan S, Finucane B. , et al. Gender, genotype, and phenotype differences in Smith-Magenis syndrome: a meta-analysis of 105 cases. Clin Genet 2007; 71 (06) 540-550
- 7 Greenberg F, Lewis RA, Potocki L. , et al. Multi-disciplinary clinical study of Smith-Magenis syndrome (deletion 17p11.2). Am J Med Genet 1996; 62 (03) 247-254
- 8 Dykens EM, Smith AC. Distinctiveness and correlates of maladaptive behaviour in children and adolescents with Smith-Magenis syndrome. J Intellect Disabil Res 1998; 42 (Pt 6): 481-489
- 9 Trask BJ, Mefford H, van den Engh G. , et al. Quantification by flow cytometry of chromosome-17 deletions in Smith-Magenis syndrome patients. Hum Genet 1996; 98 (06) 710-718
- 10 Kondo I, Matsuura S, Kuwajima K. , et al. Diagnostic hand anomalies in Smith-Magenis syndrome: four new patients with del (17)(p11.2p11.2). Am J Med Genet 1991; 41 (02) 225-229