Williams-Beuren syndrome: phenotypic variability and deletions of chromosomes 7, 11, and 22 in a series of 52 patients.
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.
Joyce
C A
CA
Genetics Laboratory, Salisbury District Hospital, UK.
Zorich
B
B
Pike
S J
SJ
Barber
J C
JC
Dennis
N R
NR
D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics; D004549:Elastin / Q000235:genetics; D005260:Female; D017353:Gene Deletion; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008297:Male; D010641:Phenotype; D011666:Pulmonary Valve Stenosis; D012303:Ring Chromosomes; D018980:Williams Syndrome / Q000175:diagnosis / Q000235:genetics*
D004549:Elastin