OBJECTIVETo investigate the clinical and cytogenetic characteristics of high-level mixed-lineage leukaemia (MLL) gene amplification in patients with acute myeloid leukemia (AML).

METHODSThe clinical and cytogenetic data of 2 AML patients with high-level MLL amplification from January 2010 to August 2016 were analyzed retrospectively.

RESULTSThe two AML cases were in middle-aged population. They were diagnosed as FAB subtype M5b and M2a respectively. Both of them had complex karyotypes with the aberrations of chromosome 11. One case was confirmed as MLL-PTD involving exons 2-9 by RT-PCR and sequencing. The other case without MLL-PTD was further analyzed by CytoScan HD analysis. The CMA results showed partial gain of 11q accompanied with partial loss in 11q, deletion of regions in 3p, 3q, 4q, 5q, 7q, 8q, 10p, 10q, 12p and 18q, as well as gain of 4p.

CONCLUSIONThe co-existence of -5/5q-, -7/7q- and highly complex karyotype may accelerate the poor prognosis. Thus how those cytogenetic abnormalities influencing the disease prognosis need to be further explored.