[Clinical characterization, molecular and FISH studies in 80 patients with clinical suspicion of Williams-Beuren syndrome].

BACKGROUND

Williams-Beuren syndrome is a developmental disorder affecting vascular and connective tissues and central nervous system. The syndrome is caused by a submicroscopic deletion in the chromosome 7 implicating the 7q11.23 region. Fluorescence in situ hybridization (FISH) and molecular studies allow us to confirm the clinical suspicion of this syndrome.

PATIENTS AND METHODS

We report clinical evaluation, FISH using Elastin Williams/D7S427 probe and molecular study with markers: D7S672, D7S653, D7S489B, D7S2476, D7S1870 and D7S489A, in 80 patients referred to test for Williams-Beuren syndrome.

RESULTS

We found hemizygosity for the critical region in 36 patients. From 69 cases studied by FISH, 28 showed the deletion. Molecular studies in 78 cases showed loss of heterozygosity (LOH) in 26 patients. The patients presented the deletion from the paternal or maternal chromosome at equal frequency. Clinical evaluation of mental retardation, facial features, esotopia dental, malocclusion, hoarse voice, supravalvular aortic stenosis (SVAS), hernias, join limitation, WBS personality and mental retardation from positive and negative patients showed estatistical significant differences for all items except mental retardation and joint limitation. The most significant item was the presence of SVAS.

CONCLUSION

This study confirms the usefulness of genetic studies as a diagnostic tool for William-Beuren Syndrome.