Department of Pediatrics, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
Int J Hematol. 2010 Sep;92(2):386-90. doi: 10.1007/s12185-010-0663-0. Epub 2010 Sep 1.
In some cases of childhood acute megakaryoblastic leukemia (AMKL), G-band analysis reveals supernumerary ring/marker chromosomes along with monosomy 7. However, their origin and relevance are poorly understood. We experienced three patients with AMKL, one of whom had Down's syndrome, whose blasts at the first visit exhibited both monosomy 7 and a ring/marker chromosome. For one case, precise molecular-cytogenetic techniques revealed that the ring chromosome was derived from a chromosome 7. It was strongly suggested that the ring chromosome was derived from a chromosome 7 in another case. The ring or one of the 2 marker chromosomes was derived from a chromosome 7 in the other case. All patients responded well to initial induction therapy. While it is not clear whether the ring/marker chromosome 7 affects the long-term prognosis of acute myeloid leukemia with monosomy 7, it may be of prognostic relevance to distinguish pure monosomy 7 from monosomy 7 with a ring/marker chromosome 7. For this purpose, conventional G-banding could be complemented with additional techniques such as spectral karyotyping or fluorescence in situ hybridization, which characterize the aberration in more detail. These methods may be useful for determining the optimal treatment and for elucidating the etiology of AMKL itself.
在某些儿童急性巨核细胞白血病 (AMKL) 病例中，G 带分析显示存在额外的环状/标记染色体，同时伴有 7 号单体。然而，其起源和相关性尚不清楚。我们遇到了 3 名 AMKL 患者，其中 1 名患有唐氏综合征，其首次就诊时的blasts 同时存在 7 号单体和环状/标记染色体。对于其中 1 例，精确的分子细胞遗传学技术显示环状染色体源自 7 号染色体。强烈提示另 1 例环状染色体源自 7 号染色体。还有 1 例环状或 2 个标记染色体中的一个源自 7 号染色体。所有患者对初始诱导治疗反应良好。虽然目前尚不清楚 7 号单体的急性髓细胞白血病中环状/标记染色体 7 是否会影响长期预后，但它可能与预后相关，可以将单纯 7 号单体与环状/标记染色体 7 区分开来。为此，可以用额外的技术（如光谱核型分析或荧光原位杂交）补充常规 G 带分析，更详细地描述这种畸变。这些方法可能有助于确定最佳治疗方法，并阐明 AMKL 本身的病因。
