D18S51及其侧翼区3个SNP组成的SNP-STR在亲子鉴定中的应用

目的将一个单倍型区块内的遗传标记单核苷酸多态性(SNP)和短串联重复序列(STR)组成SNPSTR单倍型,调查其在成都汉族人群中的分布,并探讨其在特殊亲子鉴定案例中的应用价值。方法选取DNA联合索引系统(combined DNA index system,CODIS)中突变率较高的基因座D18S51,与其侧翼区的3个SNP位点(rs8089331、rs8094489、rs7236090)组成SNP-STR,通过巢式等位基因特异性PCR的方法获得SNP-STR单倍型,调查该单倍型在75名成都汉族人群中的分布,并应用于两例D18S51基因座不符合遗传规律的二联体亲子鉴定案件。结果成功建立SNP-STR分型方法,在成都汉族人群中共发现43种单倍型,多态性为0.948 6,并成功解决了两例二联体亲子鉴定案件。结论 SNP-STR具有良好的多态性,有望应用于特殊的亲缘关系鉴定。

Application of SNP-STR Composed by D18S51 and Three SNPs of Its Flanking Region in Paternity Testing

Objective To develop a SNP-STR haplotype by consisting of the SNP and STR genetic markers, both of which locate in a haplotype block. To investigate its distribution in Han population from Chengdu, and explore its application in some special cases of paternity testing. Methods D18S51, one of the high mutation rate STR markers in combined DNA index system (CODIS), and three SNP loci rs8089331, rs8094489 and rs7236090 in its flanking region, were chosen to establish SNP-STR. Its haplotype was obtained by nested allele-specific polymerase chain reaction, and the relevant distribution of 75 unrelated individuals were investigated in Han population from Chengdu. The SNP-STR haplotype was tentatively applied in duo paternity testing cases with D18S51 incompatibility. Results The SNP-STR typing method was established and a total of 43 haplotypes were obtained successfully in Han popula-tion from Chengdu. Its polymorphism was 0.9486, and duo paternity testing cases were resolved by this method. Conclusion SNP-STR shows high diversity and can be applied in the identifications of some special paternity testing cases.