Barrows G H
Department of Pathology, Saint Francis Medical Center, Hartford, CT 06105.
Ann Clin Lab Sci. 1989 May-Jun;19(3):139-45.
Recent advances in molecular genetics have allowed development of short segments of desoxyribonucleic acid (DNA) which are complementary to active genetic sites. By pairing normal DNA with these "molecular probes", the presence of specific genetic sequences may be detected in patient samples. The majority of hematologic diseases arise from hereditary errors, neoplastic change or parasitic organisms. These types of disorders are particularly suited to diagnosis and management using detection of abnormal DNA sequences. Sensitive laboratory techniques employing these molecular probes are now available directly to detect target DNA sequences, assess abnormal short sequences of DNA, and evaluate the presence of abnormal DNA from its transcription products. Using DNA polymerase amplification, the sensitivity of these methods approaches its theoretical limitation of a single gene pair. In hematology, a prevalent application has been the detection of clonal molecular rearrangements which serves as a marker for lymphocytic neoplasia. Other applications of these techniques include the detection of abnormal chromosomal regions such as the Philadelphia chromosome and the detection of deletions of DNA which occur in such diseases as the myeloid dysplastic syndrome. As more human genetic sequences are known, it seems likely that these techniques will become prevalent among methods of laboratory testing.
分子遗传学的最新进展使得能够开发出与活性基因位点互补的脱氧核糖核酸（DNA）短片段。通过将正常DNA与这些“分子探针”配对，可以在患者样本中检测到特定基因序列的存在。大多数血液系统疾病源于遗传错误、肿瘤性改变或寄生生物。这些类型的疾病特别适合使用检测异常DNA序列的方法进行诊断和管理。现在已有采用这些分子探针的灵敏实验室技术，可直接检测目标DNA序列、评估DNA的异常短序列，并从其转录产物评估异常DNA的存在。使用DNA聚合酶扩增，这些方法的灵敏度接近其单基因对的理论极限。在血液学中，一个普遍的应用是检测克隆性分子重排，这可作为淋巴细胞肿瘤的标志物。这些技术的其他应用包括检测异常染色体区域，如费城染色体，以及检测在骨髓增生异常综合征等疾病中出现的DNA缺失。随着更多人类基因序列被知晓，这些技术似乎很可能会在实验室检测方法中变得普遍。
