By combining the PAX3/FKHR RT-PCR assay with primers for detection of the Ewing's sarcoma t(11;22) encoded EWS/FLI-1 chimeric transcript, we have developed a multiplex RT-PCR reaction that allows the rapid and accurate identification of either translocation in a biopsy sample..     ///    "To define the morphological spectrum of childhood sarcomas that express the t(2;13) encoded PAX3/FKHR chimeric message, we have performed RT-PCR analysis on samples from 44 primary pediatric sarcomas and 8 sarcoma cell lines. "    ///    "Chimeric transcripts were detected in all cases with cytogenetic evidence of the (2;13) translocation, and in each case the chimeric PAX3/FKHR message had the identical junction sequence, suggesting that genomic chromosome breaks were clustered in a single intron in both genes. "    ///    "PAX3/FKHR chimeric messages were detected in 24 of 27 alveolar, 2 of 12 embryonal, and 0 of 1 pleomorphic rhabdomyosarcoma and in 1 of 2 ectomesenchymomas. "