TELOMERE FUSION AS A MECHANISM FOR THE PROGRESSIVE LOSS OF THE SHORT ARM OF CHROMOSOME-11 IN AN ANAPLASTIC WILMS-TURNER

Wilms' tumor (WT) is associated with chromosomal deletions and loss of heterozygosity (LOH) of alleles at 11p13. The authors report the youn gest known patient with diffusely anaplastic WT and, to their knowledg e, the first case to demonstrate telomeric fusions as a chromosomal me chanism for the loss of bands 11p13 and 11p15 in WT. Recurrent clonal telomeric association (tas) initiated breakage/fusion cycles that resu lted in deletions of chromosome bands 11p15, 11p13, and, subsequently, the entire short arm of chromosome 11. In addition, tas involving the long arms of chromosomes 7 and 9 resulted in the subsequent deletion of the long arm of chromosome 7. This report expands the spectrum of c hromosomal mechanisms that can account for the loss of alleles on the short arm of chromosome 11 in WT by providing evidence that the progre ssive loss of critical chromosome regions associated with tumor suppre ssion may occur as a result of chromosomal instability initiated by ta s.