[A clinical and laboratory study on acute myeloid leukemia with t(6;9)(p23;q34)].

OBJECTIVE

To explore the clinical and laboratory features of 6 cases of acute myeloid leukemia (AML) with t(6;9)(p23;q34).

METHODS

Chromosome preparation of bone marrow cells was performed with regular method. R-banding by heating using Giemsa banding technique (RHG) was used for karyotype analysis. The immunoprofile was studied by flow cytometry (FCM) using a panel of monoclonal antibodies. Chromosome painting was performed by using whole chromosome paint probes for chromosomes 6 and 9 in all the 6 cases. The expression of fusion gene DEK/CAN and FLT3-ITD mutation were analyzed by reverse transcription-PCR(RT-PCR).

RESULTS

The t(6;9)(p23;q34) was found in all the 6 cases including 4 cases of M2 and 2 cases of M4. Blast cells were positive for CD13 and CD33 in 6 patients, for HLA-DR in 4 patients, for CD34 and CD117 in 3 cases, for CD38 or CD15 each in 1 case, respectively. A reciprocal translocation between chromosome 6 and 9 was confirmed by chromosome painting technique in the 6 cases. The DEK/CAN fusion gene was found in all the 6 cases, FLT3-ITD mutation was detected in three of them. Follow-up showed that 3 patients died with a survival time of 3 months, 5 months and 6 months, respectively. The other three obtained complete remission and are still alive.

CONCLUSION

The t(6;9)(p23;q34) is a rare recurrent abnormity. AML with t(6;9)(p23;q34) has unique clinical and laboratory features and its prognosis is poor in most cases.