天津汉族群体D21S11、D21S1440和Penta D STR基因座遗传多态性的研究

目的:研究天津汉族群体21号染色体上D21S11、D21S1440和Penta D 3个短串联重复序列(STR)基因座遗传多态性,为唐氏综合征(DS)基因诊断和产前基因诊断提供实验依据.方法:收集天津无亲缘关系的汉族个体332例,定量荧光PCR(QF-PCR)扩增STR基因座,ABI PRISM 377测序仪检测PCR扩增产物.根据3个STR基因座的基因型分布进行Hardy-Weinberg平衡检验.计算3个STR基因座的基因型频率、观察杂合度(Ho)、多态信息量(PIC)、个体识别率(DP)、非父排除率(PE)等群体遗传学数据.结果:D21S11、D21S1440和Penta D 3个STR基因座分别检出6、4、8个等位基因,基因型分布均符合Hardy-Weinberg平衡定律.3个基因座的Ho分别为0.617、0.705、0.867,PIC分别为0.755、0.596、0.795,DP分别为0.916、0.794、0.931,PE分别为0.312、0.436、0.730.结论:D21S11、D21S1440和Penta D STR基因座在天津汉族群体杂合度高,是21号染色体良好的遗传标记,对DS的基因诊断有指导意义.

Genetic Polymorphisms of STR Loci D21S11,D21S1440 and Penta D in Tianjin Han Population

Objective : To investigate the genetic polymorphisms of 3 short tandem repeat (STR) loci D21S11 , D21S1440 and Penta D on chromosome 21 in Tianjin Han population and to provide basic data for the use of 3 STR loci in gene diagnosis and prenatal gene diagnosis of Down syndrome (DS). Methods: Blood samples were collected from 332 unre-lated individuals of Tianjin Han population. QF-PCR and ABI PRISM 377 DNA sequencer were used. The frequencies of the genotypes were tested with Hardy-Weinberg equilibrium. Genetic analysis was performed to conclude some data of population genetics such as the frequency of the alleles , the heterozygosity of observation(Ho) , the polymorphism information content (PIC) , the probability of discrimination power(DP) and the probability of exclusion(PE). Results: Six, four and eight alleles of D21S11 , D21S1440 and Penta D were observed respectively. The frequencies of the genotypes were in good agreement with Hardy-Weinberg equilibrium. The Ho of 3 STR loci were 0.617, 0.705 and 0.867. The PIC were 0.755, 0.596 and 0.795. The DP were 0.916, 0.794 and 0.931. The PE were 0.312, 0.436 and 0.730. Conclusion: D21S11 , D21S1440 and Penta D STR loci had high heterozygosity in Tianjin Han population, which were good genetic markers of chromosome 21 and can be used in gene diagnosis and prenatal gene diagnosis of DS.