根据ABO基因座第6和7外显子9个SNP位点设计引物,复合扩增后直接测序,根据测序结果判定不同物证检材ABO基因型及其在藏族群体中的多态性分布。成功地检测出经过不同方法处理的血痕、毛发、口腔拭子、骨骼、混合斑等101例腐败、降解及微量检材的ABO基因型,结果与免疫血清学分型一致,且该方法具有灵敏度高、特异性好、操作简单、结果准确、客观及能够发现新等位基因等优点。对80名青海藏族无关个体的调查表明,ABO基因型分布符合Hardy-Weinberg平衡,杂合度日为0.675,多态信息含量PIC为0.672,个人识别力DP值为0.874,非父排除率PE值为0.391,偶合度I为0.126;青海藏族ABO等位基因频率O〉B〉A,且O等位基因频率高达0.6125。多重PCR-直接测序法检测ABO基因型适用于法医学不同来源的样本,提高了ABO血型系统的个体识别能力;ABO基因型在青海藏族人群中的分布具有较高多态性,可用于法医学个体识别及群体遗传学研究。
Multiplex PCR-direct sequencing method was established to detect 9 different SNPs in exon 6 and exon 7 of ABO genes and could identify at least 28 different ABO genotypes. Population study was carried out in a sample of 80 unrelated Chinese Tibetan minority individual dwelled in Qinghai Province. The method was also applied to forensic cases. A variety of degeneration forensic samples, including blood stain, hair root, swab, bone and mixed stain were successfully identified by this efficient method and in conformance with serological typing. There were no significant deviations from Hardy-Weinberg equilibrium in ABO genotypes of Tibetan population. The heterozygosity, polymorphic information content,discrimination power, paternity of exclusion, and probability of genetic identity were 0.675, 0.672, 0.874, 0.391, and 0.126 respectively. The gene frequency of ABO was O〉B〉A. The multiplex PCR-directed sequencing method can accurately and reliably detect ABO genotypes in many kinds of samples, and it improves personal identification efficiency. The ABO genotype is high variance in Qinghai Tibetan minority group, and it can be applied in forensic medicine and population genetic study.