Gerhardus Ansgar, Schleberger Henriette, Schlegelberger Brigitte, Gadzicki Dorothea
Department of Epidemiology & International Public Health, University of Bielefeld, D-33501 Bielefeld, Germany.
Eur J Hum Genet. 2007 Jun;15(6):619-27. doi: 10.1038/sj.ejhg.5201806. Epub 2007 Mar 7.
As sequence analysis for BRCA1 and BRCA2 mutations is both time- and cost-intensive, current strategies often include scanning techniques to identify fragments containing genetic sequence alterations. However, a systematic assessment of the diagnostic accuracy has been lacking so far. Here, we report on a systematic review to assess the internal and external validity of current scanning techniques. Inclusion criteria were: controlled design, investigators blinded, and tests suitable as a scanning tool for the whole genes BRCA1 and BRCA2. Outcome parameters were sensitivity, specificity, and positive and negative predictive values compared to direct sequencing. Out of 3816 publications, 10 studies reporting on 12 methods met our inclusion criteria. The internal and external validity of most of these studies was limited. Sensitivities were reported to be 100% for enzymatic mutation detection (EMD), multiple-dye cleavase fragment length polymorphism (MD-CFLP), fluorescence-based conformation-sensitive gel electrophoresis (F-CSGE), RNA-based sequencing, restriction endonuclease fingerprinting-single strand conformation polymorphism (REF-SSCP), stop codon (SC) assay, and denaturing high-performance liquid chromatography (DHPLC). Sensitivity was 50-96% for SSCP, 88-91% for two-dimensional gene scanning (TDGS), 76% for conformation-sensitive gel electrophoresis (CSGE), 75% for protein truncation test (PTT), and 58% for micronucleus test (MNT). Specificities close to 100% were reported, except for MNT. PTT and SC assay are only able to detect truncating mutations. Most studies were designed to introduce new experimental approaches or modifications of established methods and require further evaluation. F-CSGE, REF-SSCP, RNA-based sequencing, EMD, and MD-CFLP will need further evaluation before their use in a routine setting can be considered. SSCP, MNT, PTT, CSGE, and TDGS cannot be recommended because of their low sensitivity. DHPLC outperforms all other methods studied. However, none of the four studies evaluating DHPLC was performed on BRCA2.
由于对BRCA1和BRCA2突变进行序列分析既耗时又成本高昂，当前策略通常包括扫描技术以识别包含基因序列改变的片段。然而，迄今为止缺乏对诊断准确性的系统评估。在此，我们报告一项系统评价，以评估当前扫描技术的内部和外部有效性。纳入标准为：对照设计、研究者设盲以及适合作为BRCA1和BRCA2全基因扫描工具的检测方法。与直接测序相比，结果参数为敏感性、特异性、阳性预测值和阴性预测值。在3816篇出版物中，10项研究报告了12种方法，符合我们的纳入标准。这些研究大多的内部和外部有效性有限。据报告，酶促突变检测（EMD）、多染料裂解酶片段长度多态性（MD-CFLP）、基于荧光的构象敏感凝胶电泳（F-CSGE）、基于RNA的测序、限制性内切酶指纹图谱-单链构象多态性（REF-SSCP）、终止密码子（SC）检测和变性高效液相色谱（DHPLC）的敏感性为100%。单链构象多态性（SSCP）的敏感性为50%-96%，二维基因扫描（TDGS）为88%-91%，构象敏感凝胶电泳（CSGE）为76%，蛋白质截短检测（PTT）为75%，微核试验（MNT）为58%。除MNT外，报告的特异性接近100%。PTT和SC检测仅能检测截短突变。大多数研究旨在引入新的实验方法或对既定方法进行改进，需要进一步评估。在考虑将F-CSGE、REF-SSCP、基于RNA的测序、EMD和MD-CFLP用于常规检测之前，还需要进一步评估。由于敏感性低，不推荐使用SSCP、MNT、PTT、CSGE和TDGS。DHPLC优于所有其他研究的方法。然而，评估DHPLC的四项研究均未针对BRCA2进行。
