Objective: To explore the value of trisomy 22 ( +22) in the diagnosis of inv(16) acute myeloid leukemia (AML).
Methods: Interphase fluorescence in situ hybridization (FISH) was performed in 18 AML patients with +22. The probe was two-color break apart probe for CBFbeta with SpectrumRed on the centromeric side and SpectrumGreen on the telomeric side. The FISH results were compared with that of R-banding conventional cytogenetics (CC). Multiplex FISH (M-FISH) was used to analyze the relationship of +22 and inv(16).
Results: CC revealed inv(16) in none of the 18 AML, with +22, but FISH revealed inv (16) in 11 of them and del( 16) (q22) in one. As CC results, 9 of the 11 cases were sole +22, one complicated with trisomy 8, and one del(16) (q22). Four patients with +22 and inv(16) were analyzed by M-FISH and revealed +22 only.
Conclusion: +22 can be regarded as an important marker for the diagnosis of inv(16) AML.