A COMMON REGION OF LOSS OF HETEROZYGOSITY IN WILMS-TUMOR AND EMBRYONAL RHABDOMYOSARCOMA DISTAL TO THE D11S988 LOCUS ON CHROMOSOME 11P15.5

The development of Wilms' tumor has been associated with two genetic l oci on chromosome 11:WT1 in 11p13 and WT2 in 11p15.5. Here, we have us ed loss of heterozygosity (LOH) in Wilms' tumors to narrow the WT2 loc us distal to the D11S988 locus. A similar region was apparent for the clinically associated tumor, embryonal rhabdomyosarcoma. We have also demonstrated that a constitutional chromosome translocation breakpoint associated with Beckwith-Wiedemann syndrome and an acquired somatic c hromosome translocation breakpoint in a rhabdoid tumor each occur in t he same chromosomal interval as the smallest region of LOH in Wilms' t umors and embryonal rhabdomyosarcoma. Finally, we report the first Wil ms' tumor without a cytogenetic deletion that shows targeted LOH for 1 1p15 and 11p13 while maintaining germline status for 11p14.