Loss of MYB, (6q23)
The MYB gene (Avian myeloblastosis Viral Oncogene Homolog) plays an essential role in regulating hematopoiesis and may be involved in tumorigenesis. This gene was chosen as a 6q marker due to its distal location to the breakpoints on 6q (6q21). This test detects the number of copies of the MYB gene (6q23), using fluorescence in situ hybridization (FISH) in FFPE samples in melanoma. Copy number changes are frequent in melanoma, being indicated as an aid for the diagnosis of melanoma in skin biopsy samples.
To differentiate nevi from melanoma, a panel of 3 probes targeting RREB1 (6p), MYB (6q23) and CCND1 (11q13) genes has been developed. Melanoma is considered if complies with any of the following criteria:
- more than 55% of cells with more copies of RREB1 (6p25) than of Cep6 (6p25>Cep6)
- more than 29% ofcells with more than 2 RREB1 (6p25) signals
- more than 40% of cells with fewer copies of MYB (6q23) than of Cep6 (6q23<Cep6)
- more than 38% of cells with more than 2 copies of CCND1 (11q13)
References
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- Requena C, et al. (2012) 61(5):899-909.
- Gerami P, Zembowicz A. (2011) Arch Pathol Lab Med. 135(7):830-7.
