短串联重复序列位点的突变观察与分析

Mutations of Short Tandem Repeat Loci

目的：观察和分析Identifiler^TM系统15个短串联重复序列（STR）位点在亲子鉴定中的突变现象。方法：用Identifiler^TM试剂盒检测681例亲子鉴定案例．对其中1个STR位点不符合遗传规律者，采用非变性聚丙烯酰胺凝胶电泳和银染显色方法，增加其他STR位点检测。结果：在认定亲子关系的589例中．观察到16例1个STR位点发生突变。突变的位点包括D8S1179、D21S11、GSF1PO、D2S1338、D19S433、VWA、D18S51和FGA，其中以D21S11、FGA位点突变率最高（0．25％）；突变的等位基因来自父亲10次，来自母亲5次，无法确定1次。结论：STR位点突变是较为常见的现象，采用Identifiler^TM系统进行亲子鉴定．遇到1～2个STR位点不符合遗传规律时，有必要增加突变率低、稳定性好的STR位点进行复核。

Objective： To explore the mutations of 15 Short Tandem Repeat （STR） loci in Identifiler^TM system which are used in paternity testing. Methods： 681 cases of paternity testing were carried out using Identifiler^TM PCR Amplification Kit. When one locus exclusions were found , other loci were tested by non - denaturing polyacrylamide gel electrophoresis and silverstaining. Results： Among the 589 cases of confirmed paternity, 16 cases of single - locus mutation was observed. The mutation loci included in D8S1179. D21S11. CSF1PO, D2S1338, D19S433, VWA, D18S51and FGA. The mutation rates at D21 S11 and FGA were highest（0.25% ）. 10 events of paternal source mutations. 5 events of maternal source mutations and one events of indistinguishable mutations were observed in 16 events of STR mutation. Conclusion： Mutations of STR loci are relatively common in human genome. When one or two loci exclusions are found in paternity testing, stable STR loci with low mutation rate should be detected in addition.