Abstract: X chromosome is 154.8Mb long,and single nucleotide polymorphisms(SNPs) are the most common and informative type of genetic variation on the chromosome,occurring approximately once every kilobase.For individual identification in forensic sciences,167 SNPs located on X-chromosome were selected on the criteria of conservation and high informative(i.e.the minor allele frequency of each X-SNP locus was above 0.3 in Chinese Han populations).These loci could be typed by high throughout and sensitive analysis,and their polymorphic parameters could be valuated by statistic methods.As an alternative to nuclear DNA,SNP loci on X-chromosome has a particular advantage in resolving special parentage cases.They could also be used for gender identification and mixed stains detection.

Key words: X chromosome, SNP, polymorphism, geneticmarker, forensic medicine

摘要： 人类X染色体长154.8Mb,其上密布SNP位点,蕴涵着大量的信息。用于法医学鉴定的X-SNP标记多态性好、突变率低。本研究从Hapmap、NCBI的数据库中筛选了167个高信息量SNP位点,这些位点的等位基因在北京汉族人群中的分布频率均高于0.3,通过高通量、高灵敏度的检测方法可对各个X-SNP位点进行分型验证,通过正确的统计学分析可得到其法医学多态性参数。X-SNP位点具有一些常染色体遗传标记无法比拟的优点,作为常规STR基因座的补充,能用于解决特殊的亲子鉴定案,性别鉴定和混合斑鉴定。

关键词: X染色体, SNP, 多态性, 遗传学标记, 法医学