Johnson E J, Scherer S W, Osborne L, Tsui L C, Oscier D, Mould S, Cotter F E
LRF Department of Haematology and Oncology, Institute of Child Health, London, UK.
Blood. 1996 May 1;87(9):3579-86.
Chromosome 7 translocations, deletions, or monosomy are associated with myelodysplasia (MDS) and acute myeloid leukemia both in children and adults. These chromosomal anomalies represent one of the most common cytogenetic abnormalities associated with these diseases and usually herald a poor prognosis. In this study two cosmid DNA probes that mapped to 7q22.1 and were known to be separated by approximately 500 kb were identified to flank the proximal inversion breakpoint in a patient carrying a constitutional inversion (7q22.1-34) associated with MDS. A yeast artificial chromosome (YAC) clone that encompassed the two cosmids was identified and shown to span the breakpoint. Fluorescence in situ hybridization was then used to analyze six additional patients with myelodysplasia and chromosomal rearrangements of the 7q22 region (three patients had translocations and three carried deletions). The breakpoint in one of the patients was found to be contained within the same YAC clone that spanned the inversion breakpoint. Moreover, this same interval was determined to be absent in all three patients with chromosomal deletions. These results suggest that this segment of DNA on chromosome 7q22.1 may contain specific gene(s) that have a significant role in myeloid malignancies.
7号染色体易位、缺失或单体性在儿童和成人中均与骨髓增生异常综合征（MDS）及急性髓系白血病相关。这些染色体异常是与这些疾病相关的最常见细胞遗传学异常之一，通常预示着预后不良。在本研究中，鉴定出两个定位在7q22.1且已知相隔约500 kb的黏粒DNA探针，它们位于一名患有与MDS相关的先天性倒位（7q22.1-34）患者的近端倒位断点两侧。鉴定出一个包含这两个黏粒的酵母人工染色体（YAC）克隆，并显示其跨越断点。然后利用荧光原位杂交技术分析另外6例患有骨髓增生异常综合征且7q22区域存在染色体重排的患者（3例患者有易位，3例有缺失）。发现其中一名患者的断点包含在跨越倒位断点的同一个YAC克隆内。此外，确定在所有3例染色体缺失患者中该相同区间均不存在。这些结果表明，7号染色体q22.1上的这段DNA可能包含在髓系恶性肿瘤中起重要作用的特定基因。
