Study on clinical and molecular biological characteristics of infant acute leukemia

OBJECTIVE: To study the clinical and molecular biological characteristics of infant acute leukemia (IAL). METHODS: R and/or G banding technique was used for analysis of karyotype. DNA blotting for HRX gene rearrangement, and polymerase chain reaction (PCR) and reverse transcriptase PCR (RT-PCR) for fusion gene detection. RESULTS: Twenty cases of IAL were detected. HRX gene rearrangement was found in 10 cases, including HRX/AF-4 fusion gene in 5, HRX/AF-9 fusion in 2, and HRX/ENL fusion in 1, HRX self-fusion mediated by alu-repeat homologous recombination and HRX/EEN fusion each in one (HRX/EEN is a novel fusion gene reported for the first time). CONCLUSION: High frequency of HRX gene rearrangement occurred in IAL, which is characterised by a massive leukemia cell burden and 11q23 translocation, forming fusion genes, especially HRX/AF-4 (about 50%). The results are of important significance in guiding clinical treatment and approaching the etiology of IAL.