STRtyper-10G系统9个STR基因座突变分析

目的观察和分析STRtyper-10G系统9个STR基因座的突变特点。方法在7 707例肯定亲子关系的案件中,统计使用STRtyper-10G试剂盒（9个STR基因座）检测发现的突变事件,判断突变等位基因的来源,计算各基因座的突变率,分析突变特点。结果在9个基因座上共发现118个突变事件,均为1步突变;平均突变率为1.69×10-3（95%CI 1.40×10-3~2.03×10-3）,各基因座的突变率介于0.78×10-3~2.84×10-3,父、母来源突变比例为9.64∶1;短、中、长等位基因的突变比值约为1∶8∶3,增加和减少重复单位的突变比值为1.29∶1。结论 9个基因座的突变率存在显著差异,实际检案时应结合各基因座的突变率进行PI值计算更为科学。

Mutations of 9 short tandem repeat loci in STRtyper-10G system

Objective To observe and analyze the characteristics of mutation in 9 STR loci. Methods 7 707 parentage confirmed cases detected by STRtyper-10G System were analyzed. The mutation events in 9 STR loci of STRtyper-10G System were screened. The sources of mutant alleles were analyzed. The mutation rates of STR loci were calculated. The feature of mutation was analyzed. Results 118 mutation events were observed in 9 STR loci. All mutations were one step. The overall mutation rate was 1.69 × 10 -3 （95% CI 1.40 × 10-3 ~ 2.03 × 10-3 ）. The locus-specific mutation rates ranged from 0. 78 × 10-3 to 2. 84 × 10 -3. The ratio of paternal mutation versus maternal mutation was 9. 64 ： 1. The ratio of short allele mutation, moderate allele mutation, long allele mutation was 1 ： 8 ： 3. The ratio of repeat gains versus repeat losses was 1.29 ： 1. Conclusion The mutation rates of 9 STR loci showed significant differences. It may be more rational that the mutation rate of each mutated locus should be considered when calculating PI value.