[Williams syndrome: new insights into genetic etiology, pathogenesis and clinical aspects].

Williams syndrome (WS) is a developmental disorder characterized by distinct facial features, congenital heart disease, mental retardation and a gregarious personality. The majority of people with this disorder have a submicroscopic deletion of genes in chromosome band 7q11.23. This deletion can be detected using fluorescence in situ hybridization (FISH). Although the condition is usually sporadic a few familial cases with autosomal dominant inheritance have been described. A clinical scoring system has been developed by Selicorni with which a diagnosis of 'Williams syndrome' can be made; in all patients in whom the diagnosis was made in this way FISH results were positive.