材料与方法
   我室在检案过程中积累的北方汉族随机个体血样， 经CHELEX-100处理[1],获得DNA样本；采用文献所述方法进行扩增及PCR产物检测[2、6]；根据国际法医血液遗传学会推荐的命名原则,按核心序列重复单位个数命名；对所得群体数据进行Hardy-Weinberg平衡检验；应用文献方法[3-5]，使用软件包对数据进行分析处理，获得等位基因频率、杂合度、多态性信息量、匹配概率、个人识别机率和非父排除率。
   结  果
   1．D3S1754基因座检测184个样本，检出9个等位基因，19种基因型（见表1），频率最高的基因是13(0.416)；D18S535基因座检测201个样本，共检出8个等位基因，25种基因型（见表2），频率最高的基因是14（0.274）。两位点在汉族群体中的多态性分布符合Hardy-Weinberg平衡。
 

   2．两位点的杂合度（He）、多态性信息量（PIC）、匹配概率（MP）个人识别率（DP）、非父排除概率（EPP）见表3。

表3.北方汉族D3S1754、D18S353基因座遗传学多态性参数

   3．将两位点应用于82例亲子鉴定中， 观察到的非父排除率D3S1754为0.3077、D18S535为0.5714。在认定父权的案例中，两位点的遗传均符合孟德尔遗传规律。
4. 北方汉族D3S1754基因型分布与成都汉族群体相比[5]，无显著性差异；D18S535基因型分布与德国人群相比有显著性差异[ 6]，表4。
                         

   讨  论
   D3S1754和D18S535位点均属四核苷酸重复，所得到的北方汉族基因频率符合Hardy-Weinberg平衡。D3S1754位点的调查结果，与成都汉族群体相比，没有检出等位基因8，检出了16, 基因型分布没有显著性差异。D18S535位点的基因型分布，与欧洲人群相比有显著的差异。上述分析结果显示，D3S1753和D18S535两个基因座对北方汉族人群来讲，其基因频率分布较好，提供的信息较大，是个人识别率高、非父排除能力较强且能稳定遗传的位点，具有较高的应用价值。

   参考文献
   1.Walsh PS,Metzger DA,Hignchi R. Chelex-100 as a medium for simple extraction of DNA for PCR based typing from forensic material. Bio Techniques. 1991,10:506-513
   2.辛军平,陈国弟,张红玲.D1S549、D3S1754和D22S683基因座在中国成都地区汉族群体中的遗传多态性研究.法律与医学杂志.1999,6(2):66-69
   3.Jones.D.A.Blood samples: Probability of discrimination. J Forensic Sci.Soc.1972,12:355-359
   4.Brenner.C and J.Morris. Paternity index calculations in single locus hypervariable DNA probes: Validation and other studies, P 21-53. In proceedings for the International Symposium on Human Identification1989. 1990, Promega Corporation, Madisom, WI.
   5.Botstein.D,R.L.White,M.Skolnick and R.W.Davis. Construction of a genetic linkage map in using restriction fragment length polymophisms. 1980,Am.J.Hum.Genet. 32:314-331
   6.P.Wiegand, M.V.Lareu, M.Schurenkamp, et al. D18S535, D16S1656 and D10S2325:three efficient short tandem repeats for forensic genetics. Int J Legal Med. 1999,112:360-363

HAN POPULATION GENETIC POLOMORPHISM DATA OF
D3S1754 AND D18S535 LOCUS IN NORTH CHINA

LU DI
Beijing Institute of Forensic Medicine and Science 100040 

Abstract：To obtain the alleles frequencies and genetic data of two STR loci(D3S1754 and D18S535) in Han population living in north china, DNA samples from EDTA-blood of unrelated individuals were amplified. The PCR products were analyzed by PAG gel vertical electrophoresis. 9 alleles and 19 genotypes were observed at D3S1754 locus, 8 alleles and 25 genotypes were observed at D18S535 locus. The allele frequencies of two loci revealed no deviation from the Hardy-Weinberg equilibrium. Comparison of population genetic data for D3S1754 showed no significant difference between two different Chinese subpopulations(North China, Cheng du area ). Comparison of population genetic data for D18S535 showed significant difference between the Chinese population and the German population data. The two loci were proved to be highly discriminating and useful in the fields of individual identification and paternity diagnosis. 
Key words: Short tandem repeat; D3S1754; D18S535; Genetic polymorphism

（作者单位：北京市高级人民法院法医技术室100040）