Cai S P, Eng B, Kan Y W, Chui D H
Department of Pathology, McMaster University Medical Centre, Hamilton, Ontario, Canada.
Hum Genet. 1991 Oct;87(6):728-30. doi: 10.1007/BF00201734.
The 1.8-kb beta-globin gene fragments of DNAs from individuals heterozygous for nine different beta-thalassemia mutations involving 1, 2, 3, 4, or 25 basepair (bp) insertions or deletions were amplified by the polymerase chain reaction (PCR). The PCR products were subjected to electrophoresis on aqueous 8% polyacrylamide gel. In each heterozygote with either a 2 to 25 bp deletion, but not with a 1 bp insertion, two slower migrating bands representing heteroduplexes in addition to the 1.8-kb homoduplex band were seen. The electrophoretic positions of these slower migrating bands were characteristic of each mutation studied. By co-amplification with known normal DNA, it was also possible to distinguish DNAs from normal individuals and from individuals who are homozygous for the small insertion/deletion mutations. These studies demonstrate that the heteroduplex formation generated in PCR can be applied as a simple method in the diagnosis of insertion/deletion mutations involving 2 to 25 bp in beta-thalassemias as well as in other genetic disorders.
对涉及1、2、3、4或25个碱基对（bp）插入或缺失的9种不同β地中海贫血突变的杂合个体的DNA的1.8 kbβ珠蛋白基因片段进行聚合酶链反应（PCR）扩增。PCR产物在8%聚丙烯酰胺水凝胶上进行电泳。在每个具有2至25 bp缺失而非1 bp插入的杂合子中，除了1.8 kb的同源双链带外，还可见到两条迁移较慢的带，代表异源双链体。这些迁移较慢的带的电泳位置是所研究的每种突变的特征。通过与已知正常DNA共同扩增，还可以区分正常个体以及小插入/缺失突变纯合个体的DNA。这些研究表明，PCR中产生的异源双链体形成可作为一种简单方法用于诊断β地中海贫血以及其他遗传疾病中涉及2至25 bp的插入/缺失突变。
