[Williams-Beuren syndrome].

Williams-Beuren syndrome (MIM 194050) is a rare genetic disease (incidence: 1/20 000) which is rather easy to identify during childhood. This developmental disorder associates cardiac defect (supra valvular aortic stenosis most often) in 75% of cases, suggestive face dysmorphism and specific cognitive and behavioural profile. Cognitive profile consists of visuo-spatial bearing deficits contrasting with a relatively well-preserved language. Affected children present with a hyper social behaviour, especially toward strangers; they have a distinctive sensitivity to noise and music. Arterial tension and renal functions have to be looked after during the whole life. Medical and educative management must be done on a multidisciplinary way combining pediatric, cardio-pediatric, orthodontic and psychological approach. Adult patients are generally not completely self-sufficient. Williams-Beuren syndrome is due to a chromosomal microdeletion in the q11.23 region of one chromosome 7. It can not be seen on a conventional karyotype and is detected by a FISH (fluorescent in situ hybridization) analyse. This microdeletion leads to the suppression of many genes, mainly the elastin gene.