7 CASES OF WIEDEMANN-BECKWITH-SYNDROME, INCLUDING THE FIRST REPORTED CASE OF MOSAIC PATERNAL ISODISOMY ALONG THE WHOLE CHROMOSOME-11

Genomic imprinting of chromosome arm 11p is involved in the Wiedemann- Beckwith syndrome (WBS). About 20% of patients with sporadic WBS have paternal uniparental disomy (UPD) of 11p. Mitotic recombination at the 11p region has been suggested to be responsible for the somatic mosai cism in these patients. Our current study concerning sporadic WBS pati ents demonstrated six patients with mosaic isodisomy restricted to par t of 11p and one patient with mosaic paternal uniparental disomy for t he whole chromosome II. Apparently the clinical findings for this pati ent did not differ from data reported for other WBS patients. This cas e makes it unlikely that the proximal short arm and the long arm of ch romosome 11 contain imprinted genes with a phenotype recognizable pren atally or in infancy, and gives some support to the hypothesis that no n-mosaic UPD-11 is prenatally lethal. Am. J. Med. Genet. 79:347-353, 1 998. (C) 1998 Wiley-Liss, Inc.