亲子鉴定中STR基因座的基因突变分析

目的探讨Identifiler^TM荧光标记复合扩增试剂盒15个STR基因座在亲子鉴定中的基因突变特点。方法应用Identifiler^TM荧光标记复合扩增试剂盒检测676例亲子鉴定案，对其中1～2个突变基因座加做HLA等位基因检测或Y—STR基因座检测。结果在认定亲子关系的676例中，观察1304次减数分裂，Identifiler^TM荧光标记复合扩增试剂盒中的15个基因座确定19例突变，其中D18S51基因座4例，D2S1338基因座3例，D8S1179、D16S539、vWA、D7S820、D13S317基因座各2例，D5S818和TH01基因座各1例，D21S11、FGA、D3S1358、D19S433、TPOX、CSF1P0基因座未见突变；一步突变的17例，二步突变的为1例，四步突变的1例；1个基因座发生突变的18例，2个基因座同时发生基因突变的为1例；突变来自父亲与来自母亲的比例为13：2，4例来源不能确定。结论用Identifiler^TM荧光标记复合扩增试剂盒检测到1—2个基因座发生突变，须增加对其它遗传标记的检测。

Analysis on the allele mutations of STR loci in paternity testing

Objective To analyze the characteristic of allele mutations of 15 short tandem repeats in paternity testing.Methods 676 paternity testing cases were detected by using IdentifilerTM system.When one or two-locus exclusions had been observed,further examination was performed by using HLA system or Y-STRs typing.Results 1304 meiosis were investigated among the 676 cases of confirmed paternity,19 mutations were identified at D18S51(n=4),D2S1338(n=3),D8S1179(n=2),D16S539(n=2),vWA(n=2),D7S820(n=2),D13S317(n=2),D5S818(n=1) and TH01(n=1) loci.No mutation was observed at D21S11,FGA,D3S1358,D19S433,TPOX and CSF1P0 loci.In all of these 19 mutations,a single-step mutation Loas observed in 17 cases.A double-step mutation and a four-step mutation were observed in 1 case respectively.In addition,a single-locus mutation was observed in 18 cases,and a double-locus mutation was observed in 1 case.The ratio of paternal versus maternal mutations was 13:2,and four indistinguishable mutations were observed.Conclusion In paternity testing,when one or two STR mutations were observed using the IdentifilerTM system,other more genetic markers should be added to avoid the false conclusion.