Williams-Beuren syndrome: phenotypic variability and deletions of chromosomes 7, 11, and 22 in a series of 52 patients

J Med Genet. 1996 Dec;33(12):986-92. doi: 10.1136/jmg.33.12.986.

Abstract

Fluorescence in situ hybridisation (FISH) and conventional chromosome analysis were performed on a series of 52 patients with classical Williams-Beuren syndrome (WBS), suspected WBS, or supravalvular aortic stenosis (SVAS). In the classical WBS group, 22/23 (96%) had a submicroscopic deletion of the elastin locus on chromosome 7, but the remaining patient had a unique interstitial deletion of chromosome 11 (del(11)(q13.5q14.2)). In the suspected WBS group 2/22 (9%) patients had elastin deletions but a third patient had a complex karyotype including a ring chromosome 22 with a deletion of the long arm (r(22)(p11-->q13)). In the SVAS group, 1/7 (14%) had an elastin gene deletion, despite having normal development and minimal signs of WBS. Overall, some patients with submicroscopic elastin deletions have fewer features of Williams-Beuren syndrome than those with other cytogenetic abnormalities. These results, therefore, emphasise the importance of a combined conventional and molecular cytogenetic approach to diagnosis and suggest that the degree to which submicroscopic deletions of chromosome 7 extend beyond the elastin locus may explain some of the phenotypic variability found in Williams-Beuren syndrome.

MeSH terms

  • Child
  • Child, Preschool
  • Chromosome Deletion*
  • Chromosomes, Human, Pair 11 / genetics
  • Chromosomes, Human, Pair 22 / genetics
  • Chromosomes, Human, Pair 7 / genetics
  • Elastin / genetics
  • Female
  • Gene Deletion
  • Genetic Variation*
  • Genotype
  • Humans
  • In Situ Hybridization, Fluorescence
  • Infant
  • Male
  • Phenotype
  • Pulmonary Valve Stenosis
  • Ring Chromosomes
  • Williams Syndrome / diagnosis
  • Williams Syndrome / genetics*

Substances

  • Elastin