[Molecular cytogenetic characterization of five patients with myeloid leukemia and t(12;22)(p13;q12)].

Objective To explore the clinical and laboratory characteristics of 5 patients with myeloid leukemia and t(12; 22)(p13; q12). Methods Bone marrow cells were cultured for 24 h and analyzed by standard R-banding. Rearrangement of the MN1 gene was detected by fluorescence in situ hybridization (FISH) using dual color break-apart MN1 probes. MN1-ETV6 and ETV6-MN1 fusion genes were detected by reverse transcription polymerase chain reaction (RT-PCR). And the products were subjected to direct sequencing. Results Among the 5 patients, 2 had AML-M0, 2 had AML-M4, and 1 had CMM0L at the initial diagnosis. t(12; 22)(p13; q12) was the primary abnormality among all patients. Rearrangements of MN1 gene were detected by FISH in all patients. MN1-ETV6 and ETV6-MN1 fusion genes were detected respectively in 4 and 3 patients. Conclusion t(12; 22)(p13; q12) is a rare but recurrent chromosomal abnormality in myeloid leukemia, and is related to poor prognosis. allo-SCT is valuable for patients with t(12; 22)(p13; q12). Key words: MN1-ETV6 fusion gene; Recurrent chromosome abnormality; Myeloid leukemia