[Chromosome aberrations in children with the Williams-Beuren syndrome]

Karyotypic examinations were carried out in 10 children suffering from Williams-Beuren's syndrome. Chromosomal aberrations were established in two of the children. In one case the mosaic pattern of Klinefelter's syndrome was recorded, evidently presenting an instance of coincidence. In the other case deletion of the long arm of chromosome 6 (q22.2q23) was demonstrated, which according to the authors' hypothesis may represent an alternative localization of the phenotypic traits of Williams-Beuren's syndrome or of its assumed underlying defect, namely derangement of the regulation of calcium metabolism. The value of cytogenetic examination of children with Williams-Beuren's syndrome in elucidating the so far obscure pathogenesis of this disease is being emphasized.