<scp>Smith‐Magenis</scp> syndrome: Clinical and behavioral characteristics in a large retrospective cohort
Nicolas Rive Le Gouard, Adeline Jacquinet, Lyse Ruaud, Hélène Deleersnyder, Faustine Ageorges, Jennifer Gallard, Didier Lacombe, Sylvie Odent, Myriam Mikaty, Sylvie Manouvrier‐Hanu, Jamal Ghoumid, David Geneviève, Natacha Lehman, Nicole Philip, Patrick Edery, Delphine Héron, Coralie Rastel, Sophie Chancenotte, Christel Thauvin‐Robinet, Laurence Faivre, Laurence Perrin, Alain Verloès
Abstract
Smith-Magenis syndrome (SMS), characterized by dysmorphic features, neurodevelopmental disorder, and sleep disturbance, is due to an interstitial deletion of chromosome 17p11.2 (90%) or to point mutations in the RAI1 gene. In this retrospective cohort, we studied the clinical, cognitive, and behavioral profile of 47 European patients with SMS caused by a 17p11.2 deletion. We update the clinical and neurobehavioral profile of SMS. Intrauterine growth was normal in most patients. Prenatal anomalies were reported in 15%. 60% of our patients older than 10 years were overweight. Prevalence of heart defects (6.5% tetralogy of Fallot, 6.5% pulmonary stenosis), ophthalmological problems (89%), scoliosis (43%), or deafness (32%) were consistent with previous reports. Epilepsy was uncommon (2%). We identified a high prevalence of obstipation (45%). All patients had learning difficulties and developmental delay, but ID range was wide and 10% of patients had IQ in the normal range. Behavioral problems included temper tantrums and other difficult behaviors (84%) and night-time awakenings (86%). Optimal care of SMS children is multidisciplinary and requires important parental involvement. In our series, half of patients were able to follow adapted schooling, but 70% of parents had to adapt their working time, illustrating the medical, social, educative, and familial impact of having a child with SMS.