FUSION OF PAX7 TO FKHR BY THE VARIANT T(1,13)(P36,Q14) TRANSLOCATION IN ALVEOLAR RHABDOMYOSARCOMA

Although the t(2;13)(q35;q14) translocation has been found in most cas es of the pediatric cancer alveolar rhabdomyosarcoma, several cases ha ve been reported with a variant t(1;13)(p36;q14) translocation. Our fi ndings indicate that this t(1;13) rearranges PAX7 on chromosome 1 and fuses it to FKHR on chromosome 13. This fusion results in a chimeric t ranscript consisting of 5' PAX7 and 3' FKHR regions, which is similar to the 5' PAX3-3' FKHR transcript formed by the t(2;13). The 5' PAX3 a nd PAX7 regions encode related DNA binding domains, and therefore we p ostulate that these translocations create similar chimeric transcripti on factors that alter expression of a common group of target genes.