Genomic analysis of recurrent unbalanced translocation t(1 ; 7)(q10 ; p10) in myelodysplastic syndrome

不平衡易位t（1; 7）（q10; p10）是在骨髓增生异常综合征（MDS）和急性髓细胞性白血病中发现的复发性染色体异常，具有先前的放化疗史。我们使用双色FISH分析来研究这种易位的断点，以阐明其在MDS发病机制中的作用。结果表明，该易位发生在1号染色体上的D1 Z7和7号染色体上的D 7Z 1识别的两簇着丝粒α序列之间。然而，基于这些α信号在衍生染色体和相应的正常染色体上的FISH信号的相对强度的较大变化，每个α簇内的断裂点的位置在患者之间可能存在很大差异，表明它是7 q的丢失和/或1 q物质的获得，而不是断裂点附近的特定基因的异常，这可能是重要的MDS/AML的发病机制窝藏这种易位。

The unbalanced translocation t(l ; 7)(qlO ; plO) is a recurrent chromosomal abnormality found in myelodysplastic syndrome (MDS) and acute myelocytic leukemia with prior histories of chemoradiotherapy. We investigated the breakpoints of this translocation using two-color FISH analysis in order to clarify its roles in pathogenesis of MDS. It was revealed that the translocation occurred between two clusters of centromere alphoid sequences recognized by D1Z7 on chromosome 1 and D7Z1 on chromosome 7. Based on the large variations of relative intensities of FISH signals of these alphoid signals on the derivative chromosome and the corresponding normal chromosome, however, the location the breakpoint within each alphoid cluster may largely differs among patients, indicating that it is loss of 7q and/or gain of 1q materials, rather than the abnormalities of a specific gene near the breakpoint, that might be important for the pathogenesis of MDS/AML harboring this translocation.