云南人群1199例亲子鉴定案件基因突变分析

Observation and analysis of gene mutations in 1 199 parentage testing cases in Yunnan

目的 观察和分析PowerPlex~21 System试剂盒20个短串联重复序列（STR）基因座在云南人群亲子鉴定中的突变现象。方法 采用PowerPlex~21 System试剂盒对1 199例结论为“肯定”的亲子鉴定案件进行基因分型,对基因座存在不符合遗传规律者,判断突变等位基因类型及来源,分析基因座突变率及特点。结果1 199例亲子鉴定中,共观察到39例突变,其中38例有1个STR基因座发生突变,2个STR基因座同时突变的观察到1例。在被研究的20个常染色体STR基因座中17个基因座观察到基因突变现象,突变率在0~0.29%之间,父源与母源突变比为2.8∶1。结论 获得了云南人群20个常染色体STR基因座的突变率,本结果不仅为司法鉴定服务案件中突变情况下的亲权指数计算提供了数据支持,而且为法医学遗传标记的选择提供了客观依据。

Objective To observe and analyze the mutation phenomenon of 20 STR loci of PowerPlex 21D Kit in paternity tests among Yunnan population. Methods A total of 1 199 cases of confirmed parentage testing were gent-typed using the PowerPlex 21D kit. The mutation pattern and source were analyzed in cases with exclusion loci. The mutation rate of each STR loci was calculated. Results Among the 1 199 confirmed paternity cases, a total of 40 mutation events were observed in 39 cases, including 38 cases with single locus mutation and 1 case with mutations in two loci. In the 20 STR loci, 17 loci were found with mutation, and the mutation rates varied from 0 to 0. 29%. The ratio of paternal versus maternal mutation was 2. 8：1. Conclusion The mutation rates of 20 autosomal STR loei were obtained in Yunnan population, which was useful for CPI calculation in suspected mutation cases as well as selection of DNA marker in the fo- rensic practice.