Fishleder A J, Shadrach B, Tuttle C
Department of Laboratory Hematology, Cleveland Clinic Foundation, Ohio 44195-5139.
Leukemia. 1989 Oct;3(10):746-8.
Molecular studies have demonstrated that the Philadelphia chromosome (Ph) translocation characteristic of chronic granulocytic leukemia (CGL) and 50% of the cases of Ph positive acute lymphocytic leukemia (ALL) involves a limited 5.8 Kb region on chromosome 22 termed the breakpoint cluster region (bcr). Detection of bcr rearrangement by Southern blot analysis has proven to be a sensitive diagnostic method and can identify this translocation in some cases which appear cytogenetically negative. Restriction fragment length polymorphisms (RFLP) which involve bcr have the potential to be misinterpreted as gene rearrangements since they result in alteration of the DNA fragment size detected by Southern blot hybridization. We have identified a RFLP involving bcr that is detectable with Eco RI digestion but not with Bam HI, BgI II, or Xba I. The polymorphic fragments generated indicate that this RFLP is the result of an Eco RI restriction site sequence polymorphism.
分子研究表明，慢性粒细胞白血病（CGL）特征性的费城染色体（Ph）易位以及50%的Ph阳性急性淋巴细胞白血病（ALL）病例涉及22号染色体上一个有限的5.8千碱基区域，称为断裂点簇集区（bcr）。通过Southern印迹分析检测bcr重排已被证明是一种敏感的诊断方法，并且在一些细胞遗传学上呈阴性的病例中也能识别这种易位。涉及bcr的限制性片段长度多态性（RFLP）有可能被误判为基因重排，因为它们会导致Southern印迹杂交检测到的DNA片段大小发生改变。我们已经鉴定出一种涉及bcr的RFLP，用Eco RI消化可检测到，但用Bam HI、BgI II或Xba I消化则检测不到。产生的多态性片段表明这种RFLP是Eco RI限制性酶切位点序列多态性的结果。
