Analysis of Clinical Features of Williams-Beuren Syndrome Referred for Molecular Cytogenetic Study

Objective: Williams-Beuren syndrome (WBS) is a contiguous gene deletion disorder in which the commonly deleted region encompasses about 1.5∼2.0 Mb of DNA at 7q11.23. Clinical features of WBS change with age and vary between patients. We attempted to establish useful indicators for clinical recognition of WBS in infancy and childhood. Materials and Methods: We analyzed the clinical characteristics of 25 patients referred to us to confirm a diagnosis of WBS. Those 25 patients were classified into 3 groups: group 1, younger than 3 years; group 2, between 3 and 5 years old; and group 3, older than 5 years. A diagnosis was made by fluorescence in situ hybridization (FISH) analysis. Results: Nineteen of the 25 suspected cases (76%) were found to have deletion of the elastin gene. Nine of the 14 patients in group 1 (64.29%) had the deletion as did 5 in 6 in group 2 (83.33%) and 5 in 5 (100%) in group 3. Seventy-two percent (18/25) of patients with deletion of the elastin gene had congenital cardiovascular defects and developmental delay, 68% (17/25) had dysmorphic features, 56% (14/25) had mental retardation, 40% (10/25) had a gregarious personality, 28% (7/25) had dental abnormalities in, 4% (1/25) had strabismus, 4% (1/25) had systemic hypertension. Most of the cases (19/25) with more than 2 phenotypic features were found to have deletion of the elastin gene, particularly those with cardiovascular defects. Conclusions: The clinical characteristics, including SVAS/PPS, mental retardation, developmental delay, a dysmorphic face, dental abnormalities, and a gregarious personality may be useful indicators of WBS. Although cardiovascular defects alone cannot serve as an absolute indicator, the combination of cardiovascular defects with 1 of the other phenotypic features can help make a diagnosis of WBS.