Rodríguez Santiago, Zapata Carlos
Departamento de Biología Fundamental, Facultad de Biología, Universidad de Santiago, Santiago de Compostela, Spain.
Mol Biotechnol. 2002 Jun;21(2):117-22. doi: 10.1385/MB:21:2:117.
Dinucleotide repeats are genetic markers that are useful for many purposes, including genetic epidemiology, population genetics, and genetic diagnostics. The accuracy of analyses based on dinucleotide repeat polymorphisms is highly dependent on the success achieved in minimizing genotyping errors. Genotyping errors in dinucleotide repeat typing may arise for various reasons, including polymerase chain reaction (PCR) processing errors and the use of unsuitable electrophoretic conditions for resolving amplification products (i.e., lack of single-base resolution and inadequate precision in allele sizing). We have recently described a nondenaturing electrophoretic system useful for detecting PCR processing errors that lead to misidentification of heterozygotes as homozygotes in (AC)n repeat typing. Here, we show that this system also allows resolution of (AC)n repeats in native conditions with single-base resolution and high sizing precision, on the basis of an analysis of seven human (AC)n repeats ranging in size from 72 to 217 bp. This PAGE system is thus also useful for reducing the likelihood both of allele misidentification due to the absence of single-base resolution and of inaccuracies in allele sizing due to anomalous electrophoretic migrations among the alleles within an (AC)n repeat.
二核苷酸重复序列是一种遗传标记，在许多方面都很有用，包括遗传流行病学、群体遗传学和基因诊断。基于二核苷酸重复多态性的分析准确性高度依赖于在最小化基因分型错误方面所取得的成功。二核苷酸重复分型中的基因分型错误可能由多种原因引起，包括聚合酶链反应（PCR）处理错误以及使用不合适的电泳条件来分离扩增产物（即缺乏单碱基分辨率和等位基因大小测定精度不足）。我们最近描述了一种非变性电泳系统，该系统可用于检测在（AC）n重复分型中导致杂合子被误鉴定为纯合子的PCR处理错误。在此，我们表明，基于对7个大小从72到217 bp的人类（AC）n重复序列的分析，该系统还能够在天然条件下以单碱基分辨率和高大小测定精度解析（AC）n重复序列。因此，这种聚丙烯酰胺凝胶电泳（PAGE）系统对于降低因缺乏单碱基分辨率而导致的等位基因误鉴定以及因（AC）n重复序列中等位基因间异常电泳迁移而导致的等位基因大小测定不准确的可能性也很有用。
