Clinical and Molecular Cytogenetic Study of 38 Williams-Beuren Syndrome Tunisian Patients

Background: Williams-Beuren syndrome (WBS) is a rare multi-system genomic disorder, caused by 7q11.23 microdeletion with a prevalence of 1/7500 1/20,000 live births. Clinical phenotype includes typical facial dysmorphism (elfin face), mental retardation associated with a peculiar neuropsychological profile and congenital heart defects. Other signs are occasional like ocular, skeletal, renal and dental anomalies. Here in, we present 38 WBS Tunisian patients. Methods: All patients underwent a genetic consultation and in order to confirm the clinical diagnosis of WBS, fluorescent in situ hybridization (FISH) was applied on metaphase spreads using the dual color locus specific identifier WBS region probe (Vysis probe) that hybridized to the ELN and LIMK1 loci at 7q11.23 and to control loci D7S486 and D7S522 at 7q31. About 15 to 20 metaphases were analyzed for each case. Results: The mean age at diagnosis was 4 years and 4 months. All patients showed facial dysmorphism. 66% (23/35) have cardiovascular anomaly, peripheral pulmonary stenosis (10/35) is interestingly more frequent than the supravalvular aortic stenosis (7/35). Various degrees of mental retardation were present and a normal intelligence was found in three patients. The unique cognitive profile was found in all patients except one who had autistic disorders. Ocular anomalies (13/38) were less frequent than described, the skeletal anomalies too Corresponding author.