广东广西地区5个群体9个STR基因座的频率调查

目的 调查广东汉族、广西汉族、广西侗族、广西壮族、广西苗族5个群体9个STR基因座多态性,探讨其在法医学检验中的应用价值。方法 应用AmpFISTR Profiler PlusTM荧光标记复合扩增系统,对广东广西5个群体4个民族的1191个无关个体的血样DNA进行9个STR基因座的复合扩增;用ABI 3100遗传分析仪对扩增产物进行分型,统计9个STR基因座的群体遗传学参数。结果 9个STR基因座在广东广西地区5个群体中的累积偶合率为1.51×10-11～8.08×10-11,累积非父排除率为0.99981—0.99990。,结论 该9个STR基因座可满足汉族、壮族、侗族、苗族群体法医学的个体识别及亲权鉴定的需要。     

Typeability of AmpFlSTR SGM Plus loci in brain and thyroid gland tissue samples incubated in different environments

Autolysis and putrefaction are crucial factors responsible for degradation of cells, tissues, and organs. Postmortem changes may assume different course depending on extrinsic and intrinsic conditions. The aim of the study was assessment of environmental effect on typeability of AmpFlSTR SGM Plus loci: D3S1358, VWA, D16S539, D2S1338, D81179, D21S11, D18S51, D19S433, TH01, FGA, and gender marker amelogenin. Brain and thyroid gland tissue specimens collected during autopsies of five persons aged 20-30 years were incubated at 21 degrees C and 4 degrees C in different environmental conditions. DNA was extracted by organic method from tissue samples collected in 7-day intervals and subsequently typed using AmpFlSTR SGM Plus kit and ABI 310. A fast decrease in typeability rate was seen in specimens incubated in peat soil and in sand. Brain tissue samples were typeable in all AmpFlSTR SGM Plus loci within 126 days of incubation at 4 degrees C. Faster DNA degradation was recorded in thyroid gland specimens. In samples with negative genotyping results, no DNA was found by fluorometric quantitiation.     

Population genetic data for 18 STR loci in Costa Rica

Allele frequencies for 18 STR autosomal loci (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, D16S539, TH01, TPOX, CSF1PO, Penta D, Penta E, D19S433, D2S1338 and SE33) were obtained from a sample of 191-500 unrelated individuals from Costa Rica, Central America.     

X染色体STR单倍型DXS7424-DXS101遗传多态性

目的研究X染色体STR单倍型DXS7424-DXS101在汉族群体中的法医学特征及其分布特点。方法本实验应用PCR和聚丙烯酰胺凝胶电泳及银染技术对DXS7424和DXS101位点进行基因分型,利用相关统计方法进行数据分析。结果汉族151个男性样本中共检出37种单倍型,频率分布在0.0066～0.1391,GD值为0.9453,DP值达到0.9389,最常见单倍型为16-23。结论DXS7424-DXS101作为单倍型分析在汉族群体中具有较高的个体识别率和非父排除率,在法医学特殊亲权鉴定中具有良好的应用前景。     

用Y-STR单倍型推断男性个体来源的分析

目的 利用17个Y-STR单倍型数据,推断分析浙江绍兴地区男性个体来源,为Y-STR数据库的建设与应用提供依据.方法 采集绍兴地区6县(市)区,104个镇(乡),1240个村的138个姓氏家族的7384份男性个体血样.采用YfilerTM复合扩增试剂盒进行17个Y-STR分型,所得数据进行县(市/区)/镇(乡/街道)/村/姓氏的组合和县(市/区)/镇(乡/街道)/村/姓氏/单倍型组合分布情况统计分析.结果 在7384份男性样本中,获得2 486种县(市/区)/镇(乡/街道)/村/姓氏组合,4957种县(市/区)/镇(乡/街道)/村/姓氏/单倍型组合,3149种Y-STR单倍型.其单倍型出现的次数从1至52次不等,其中仅出现1次的有2 471种(78.47％).对出现频率为17～ 52次的单倍型数据进行姓氏分析,发现平均有71.0％ (42.9％ ～87.5％)的人员来自同一姓氏,且在地域上多数为相邻镇或村的同姓人员.结论 利用Yfiler系统的17个Y-STR基因座单倍型数据,可以推断浙江绍兴地区男性个体的地域或姓氏来源.     

Comparison of two methods for isolating DNA from human skeletal remains for STR analysis

Abstract: The quality and efficiency of a standard organic DNA isolation method and a silica‐based method using the QIAGEN Blood Maxi Kit were compared to obtain human DNA and short tandem repeats (STRs) profiles from 39 exhumed bone samples for paternity testing. DNA samples were quantified by real‐time PCR, and STR profiles were obtained using the AmpFlSTR^® Identifiler^® PCR amplification kit. Overall, the silica‐based method recovered less DNA ranging from 0 to 147.7 ng/g (average 7.57 ng/g, median = 1.3 ng/g) than did the organic method ranging from 0 to 605 ng/g (average 44.27 ng/g, median = 5.8 ng/g). Complete profiles (16/16 loci tested) were obtained from 37/39 samples (95%) using the organic method and from 9/39 samples (23%) with the silica‐based method. Compared with a standard organic DNA isolation method, our results indicate that the published silica‐based method does not improve neither the quality nor the quantity of DNA for STR profiling.     

Forensic Analysis of mtDNA Haplotypes from Two Rural Communities in Haiti Reflects Their Population History

Abstract: Very little genetic data exist on Haitians, an estimated 1.2 million of whom, not including illegal immigrants, reside in the United States. The absence of genetic data on a population of this size reduces the discriminatory power of criminal and missing‐person DNA databases in the United States and Caribbean. We present a forensic population study that provides the first genetic data set for Haiti. This study uses hypervariable segment one (HVS‐1) mitochondrial DNA (mtDNA) nucleotide sequences from 291 subjects primarily from rural areas of northern and southern Haiti, where admixture would be minimal. Our results showed that the African maternal genetic component of Haitians had slightly higher West‐Central African admixture than African‐Americans and Dominicans, but considerably less than Afro‐Brazilians. These results lay the foundation for further forensic genetics studies in the Haitian population and serve as a model for forensic mtDNA identification of individuals in other isolated or rural communities.     

强奸致孕形成部分性葡萄胎的检验分析

目的探讨强奸致孕案葡萄胎组织的DNA检验和STR结果分析。方法用DNA Typer TM15试剂盒对犯罪嫌疑人、受害人血样和流产胚胎组织进行荧光复合STR基因座扩增检测。结果检测的一例流产胚胎组织DNA的STR峰谱表现出部分3条带,且3条带中有两个等位基因来源于犯罪嫌疑人,另外一个来源于受害人,推断为单卵双精子受精的部分性葡萄胎。结论应用STR分型技术可以推断葡萄胎的DNA来源和受精类型,为亲缘关系鉴定提供依据。     

Chelex法和两种磁珠法提取接触DNA效果的比较

目的比较Chelex法、DNA IQ磁珠法、EQ国产磁珠法对接触DNA的提取效果。方法将稀释为10ng、100ng的标准品DNA,分别采用Chelex法、DNA IQ磁珠法、EQ国产磁珠法处理;对30例烟蒂和30例牙刷分别采用Chelex法、DNA IQ磁珠法和EQ国产磁珠法提取DNA,然后进行PCR定量和STR检测。结果Chelex法对DNA的提取无损失,DNA IQ磁珠法、EQ国产磁珠法对DNA的提取均有不同程度的损失;烟蒂、牙刷等检材采用Chelex法提取的接触DNA量和IPC CT值显著高于IQ磁珠法、EQ国产磁珠法,但STR检验成功率却低于IQ磁珠法、EQ国产磁珠法。2种磁珠法提取的DNA量、IPC CT值和STR检验成功率无显著性差异。结论污染轻、杂质少的接触DNA检材,用Chelex法提取最为方便快捷;IQ磁珠法、EQ国产磁珠法更适合污染接触DNA检材的提取及自动化操作。     

STRtyper-10G系统9个STR基因座突变分析

目的观察和分析STRtyper-10G系统9个STR基因座的突变特点。方法在7 707例肯定亲子关系的案件中,统计使用STRtyper-10G试剂盒（9个STR基因座）检测发现的突变事件,判断突变等位基因的来源,计算各基因座的突变率,分析突变特点。结果在9个基因座上共发现118个突变事件,均为1步突变;平均突变率为1.69×10-3（95%CI 1.40×10-3~2.03×10-3）,各基因座的突变率介于0.78×10-3~2.84×10-3,父、母来源突变比例为9.64∶1;短、中、长等位基因的突变比值约为1∶8∶3,增加和减少重复单位的突变比值为1.29∶1。结论 9个基因座的突变率存在显著差异,实际检案时应结合各基因座的突变率进行PI值计算更为科学。