The ZytoLight ® SPEC FOXO1 Dual Color Break Apart Probe is designed for the detection of specific translocations involving the chromosomal region 13q14.11 harboring the FOXO1 (forkhead box O1, a.k.a. FKHR) gene characteristic for alveolar rhabdomyosarcoma. Among solid tumors of the childhood, rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma. RMS are classified in two main categories: embryonal rhabdomyosarcoma (ERMS) and alveolar rhabdomyosarcoma (ARMS). The alveolar histology is associated with a poorer prognosis. ARMS is characterized by two tumor-specific reciprocal translocations t(2;13)(q36;q14.1) and t(1;13) (p36.1;q14.1) detectable in more than 80% of all ARMS. These translocations fuse the FOXO1 locus on 13q14.11 to either PAX3 on chromosome 2 or to PAX7 on chromosome 1. The resulting fusion transcripts encode for the chimeric proteins PAX3-FOXO1 and PAX7-FOXO1 that combine transcriptional domains from the corresponding wild-type proteins and thereby acquire oncogenic activity. The translocations and their fusion genes represent highly specific genetic markers useful in the diagnosis of ARMS.
