FISH – Alveolar Rhabdomyosarcoma (ARMS), FKHR (13q14) Rearrangement
Use
This test uses fluorescence in situ hybridization (FISH) with a break‑apart probe for the FOXO1 (FKHR) gene at 13q14 to detect rearrangements typical of alveolar rhabdomyosarcoma (ARMS), supporting histologic diagnosis in conjunction with clinical and pathologic features ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/overview/35281?utm_source=openai)).
Special Instructions
A pathology report is required. Submit either a formalin‑fixed, paraffin‑embedded (FFPE) tumor tissue block or unstained slides; preferentially blocks. Ancillary probes may be added at additional charge. Recommend express shipping. ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/overview/35281?utm_source=openai))
Limitations
Not FDA‑cleared or approved; performance characteristics established under CLIA. Alternative fixatives (non‑formalin) and decalcified tissues may reduce success; blocks may be returned. FISH will be attempted only if sufficient tumor is present; failure to show signals results in a lack of result. Only FOXO1 rearrangements detected, other chromosomal abnormalities not ruled out. ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/overview/35281?utm_source=openai))
Methodology
Chromosomal / Cytogenetics (FISH)
Biomarkers
Result Turnaround Time
7-10 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Collection Instructions
Submit a formalin‑fixed, paraffin‑embedded (FFPE) tumor tissue block; alternatively, 4 consecutive unstained, positively charged, 5 micron slides plus one H&E slide.
Causes for Rejection
Alternative fixatives and decalcified blocks have lower success; insufficient tumor may lead to cancelation or lack of result.