Practical applications of genotypic surveys for forensic STR testing

Legitimate genotype frequency estimation for multiallelic loci relies on component allele frequencies, as population surveys represent only a fraction of possible DNA profiles. Multilocus genotypes from two ethnic human populations, African American (n=195) and U.S. Caucasian (n=200), were compiled at 13 STR loci that are used worldwide in forensic investigation (D3S1358, vWA, FGA, D16S539, TH01, TPOX, CSF1PO, D8S1179, D21S11, D18S51, D5S818, D13S317, and D7S820). Sex-specific AmpFlSTR multiplexes provided stringent PCR-based STR typing specifically optimized for multicolor fluorescence detection. Heterozygosity at each STR locus ranged from 0.57 to 0.89 and encompassed from seven (TH01) to twenty-one (D21S11) alleles. Homozygosity tests, tests based on the distinct numbers of observed homozygous and heterozygous classes, log likelihood ratio tests, and exact tests assessed that the degree of divergence from theoretical Hardy-Weinberg proportions for all 13 STRs does not have practical consequence in genotype frequency estimation. Departures from linkage equilibrium, between loci, that imposed significance to forensic calculations were not indicated by observed variance of the number of heterozygous loci or Karlin interclass correlation tests. For forensic casework, reliable multilocus profile estimates may be obtained from the product of component genotype frequencies, each calculated through application of the Hardy-Weinberg equation to population database allele frequency estimates reported here. The average probability that two randomly selected, unrelated individuals possess an identical thirteen-locus DNA profile was one in 1.8x10(15) African Americans and one in 3.8x10(14) U.S. Caucasians.     

中国汉族人群15个STR基因座的等位基因频率调查

目的 调查10071名中国汉族无关个体15个STR基因座的等位基因的类型及其频率，并与以往相关文献报道的汉族群体资料进行统计比较。方法 应用PowerPlex~(TM)16荧光标记复合扩增系统，对10071份中国汉族无关个体的血样DNA进行15个STR基因座的复合扩增；用ABI 377或3100遗传分析仪对扩增产物进行分型，统计15个STR基因座的基因频率。结果 15个STR基因座共发现226个等位基因，频率在0.0001～0.5512；除D8S1179基因座外，其它基因座均发现稀有等位基因，数目1～7个不等，共34个。在中国汉族人群，稀有D21S11基因座的等位基因32.1和36.2，D18S51基因座的等位基因15.2和17.2，Penta E基因座的等位基因15.2、17.4、18.4、19.4、26和27，D7S820基因座的等位基因9.2、10.1、11.1和15，Penta D基因座的等位基因18、19和20，TPOX基因座的等位基因14，FGA基因座的等位基因13，以及较常见但欧洲稀有的D21S11基因座的等位基因30.3和D7S820基因座的等位基因9.1和9.2等均为首次报道。结论 大样本基因频率调查有利于观察STR基因座的稀有等位基因；本研究结果与以往相关文献报道的结果有不同程度的差异。     

Development of a deoxyribonucleic acid (DNA) restriction fragment length polymorphism (RFLP) database for Punjabis in East Punjab,India

In response to continuing interest in obtaining reference deoxyribonucleic acid (DNA) analysis data for previously unstudied population groups, blood samples were collected from Punjabi individuals living in East Punjab, India. This first segment of our research is focused on restriction fragment length polymorphism (RFLP) analysis, with future segments anticipated for various polymerase chain reaction (PCR) based techniques. In this study, the samples were subjected to RFLP analysis using HaeIII, followed by hybridization with variable number tandem repeat (VNTR) probes for loci D2S44, D1S7, D10S28, D4S139, D17S79 and D5S110. The band sizes of the resulting patterns were estimated using an FBI imaging system. The resulting data were subjected to statistical analysis for conformity with Hardy-Weinberg expectations, first for the total population of Punjabis, and additionally for the subgroups of Sikhs and Hindus. The loci are highly polymorphic in all sample populations studied. Except for D5S110, there is no evidence for departure from Hardy-Weinberg equilibrium (HWE) for the VNTR loci in the population groups. In addition, there is little evidence of correlation between the alleles at any of the pairs of loci and no evidence of association across the six loci. Finally, the data suggest that a multiple locus VNTR profile would be rare in the Punjabi or either of its subgroups.     

Use of combined frequencies for RFLP and PCR based loci in determining match probability

Statistical analysis was performed on a subset of the Pennsylvania State Police Caucasian, African American and Hispanic database for the purpose of determining Hardy-Weinberg equilibrium and associations across the RFLP loci D1S7, D2S44, D4S139, D5S110, D10S28 and D17S79 and the PCR-based loci HLA-DQA1, LDLR, GYPA, HBGG, D7S8 and Gc. Overall, the statistical results are consistent with a population in equilibrium both within and between loci. The assumption for independence is valid.     

荧光标记复合扩增检测4个STR基因座多态性

目的建立荧光标记复合扩增D1S2142,D13S1492,D14S306,D15S659基因座检测分型方法,并对成都汉族群体4个基因座的遗传多态性进行调查。方法用6-FAM标记D1S2142和D15S659引物,HEX、TMR分别标记D14S306和D13S1492引物,PCR复合扩增,310基因分析仪电泳自动收集电泳结果数据,GeneScan Analysis Software3.7NT软件计算扩增产物片段相对大小,Genotyper(3.7NT软件进行样本基因型分型,建立了荧光标记复合扩增检测4个STR基因座基因型的方法,对145名成都汉族无关个体样本进行分型。结果荧光标记复合扩增D1S2142,D13S1492,D14S306,D15S659基因座,每个STR基因座都获得了清晰的基因型分型结果。145份样本,4个STR基因座分别检出10,14,7,12个等位基因和22,54,21,39种基因型,其基因型分布均符合Hardy-W e inberg平衡。4个基因座在成都汉族群体的杂合度分别依次为0.7793,0.8345,0.7793和0.8345;多态信息含量分别依次为:0.7656,0.8730,0.7470和0.8312。累计非父排除率为0.9783,累计个人识别机率为0.9999 917。结论荧光标记复合扩增D1S2142,D13S1492,D14S306,D15S659基因座,可实现对每个基因座准确分型;成都汉族群体该4个基因座的遗传学数据,可为群体遗传学和法医学研究与应用提供基础资料。     

Data on the PCR Turkish population based loci: LDLR, GYPA, HBGG, D7S8, and Gc

Allele and genotype frequencies for the five PCR-based loci were analyzed in 157 unrelated Turkish individuals. The five PCR-based loci included LDLR, GYPA, HBGG, D7S8, and Gc. The results of the chi-square and exact tests showed that the genotype distribution at the LDLR, GYPA, D7S8, and Gc loci did not significantly differ from the Hardy-Weinberg Expectation (HWE). However, the genotype distribution at the HBGG locus did not conform to HWE. Moreover, the genotype frequencies calculated in this study were compared with the published genotype frequencies of US African American and US Caucasian populations. The Turkish population was significantly different at the HBGG locus from the US Caucasian population. However, there were highly significant differences at the LDLR, HBGG, and Gc loci between the Turkish and African American populations.     

A novel fluorescent quadruplex STR typing system and the allele frequency distributions in a Thai population

We have previously reported a new triplex amplification and typing system by silver staining for three short tandem repeat (STR) loci, 9q2h2 (D2S3020), D15S233, and D14S299 without "microvariant" alleles such as .1, .2, and, .3 alleles in the Japanese population. In the present study, we established a new quadruplex system with an additional locus D7S809 using primer sets labeled with fluorescent multi-color dyes. Using this system, we genotyped 183 Thai people, found only one "microvariant" allele (allele 20.2) at D7S809, and calculated allele frequencies and some statistical properties at these four STR loci. From these allele frequencies at four STR loci, we performed three statistical analyses including a homozygosity test, a likelihood ratio test, and an exact test for Hardy-Weinberg equilibrium (HWE). Deviations from HWE (p < 0.05) were observed only in the two tests at the locus D7S809. In the present study, we compared the allele frequencies at these four loci in the Thai population to those in the Japanese population described previously. Consequently, all observed heterozygosities and power of discrimination (PD) at those loci in the Thai population were higher than 0.8 and 0.9, respectively, and all statistical values for discriminating power in the Thai population were slightly higher than those in the Japanese population. The combined paternity exclusion rate (combined PE) in the Thai population (0.978) was almost the same as that in the Japanese population (0.971). Therefore, this novel PCR amplification and typing system for four STR loci would be a convenient and informative DNA profiling system in the forensic field.     

D3S1754、D18S535基因座在中国北方汉族的多态性分析

目的 了解D3S1754、D18S535基因座多态性在中国北方人群中的分布特点及其应用价值。方法 使用PCR、聚丙烯酰胺垂直板电泳及银染的方法。结果D3S1754基因座检出9个等位基因（n=184）,D185535基因座检出8个等位基因（n=201）,两个位点的等位基因频率在群体中的分布符合Hardy-Weinberg平衡（P>0.05）,它们的杂合率（He）分别为0.706和0.807,个人识别机率（DP）分别是0.859和0.934,非父排除率（EPP）分别为0.464和0.629。结论 D3S1754、D18S535两个遗传标记的个人识别率高、非父排除能力较强且能稳定遗传,具有较高的应用价值。     

The analysis of three short tandem repeat (STR) loci in the Slovene population by multiplex PCR

Allele frequencies for three tetrameric short tandem repeat (STR) loci D3S1358, HUMVWA, and HUMFGA were determined in a Slovene Caucasian population sample. DNA samples from a total of 221 Slovenes were amplified by multiplex PCR using the commercial kit AmpFISTR Blue (Perkin-Elmer). Separation and detection of the amplified STR fragments were carried out using a 377 automated genetic analyzer (Applied Biosystem Division/Perkin Elmer). Seven alleles at the D3S1358 locus, 8 alleles at the HUMVWA31A locus, and 13 alleles at the HUMFGA locus were observed. A deviation from Hardy-Weinberg equilibrium was observed, only at the HUMVWA31A locus (p = 0.045, exact test). The departure at this locus was not significant after Bonferroni correction. There were no detectable departures between pairwise comparisons of the loci. The combined power of discrimination for all three loci is 0.9998, and the power of exclusion is 0.9526. The observed allele frequencies for the loci D3S1358, HUMVWA31A, and HUMFGA are similar to those in European and U.S. Caucasian populations.     

STRs data for the loci D3S1385, vWA,FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820 from Córdoba (Argentina)

Allele and genotype frequencies for nine STRs loci included in the AmpFlSTR Profiler Plus kit (D3S1385, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820), were determined from urban and countryside population of Córdoba (Argentina). All loci meet the Hardy-Weinberg expectation, and there is little evidence for alleles association between these nine loci. The results demonstrate that these loci can be useful for databasing purposes in human identification and parentage testing in the population of Córdoba (Argentina).     

3个miniSTR基因座在湖南汉族人群中的遗传多态性

目的建立扩增片段小于120bp,包括D10S1248、D2S441和D1S16773个miniSTR基因座的复合扩增系统,并调查其在湖南汉族人群中的遗传多态性。方法采用不同荧光染料标记引物,通过PCR扩增,利用ABI 310遗传分析仪对186份无关个体血样进行3个miniSTR基因座片段长度分析。结果D10S1248、D2S441和D1S1677 miniSTR基因座均获得了清晰的基因分型结果,经对186名无关个体进行分析,分别检出9、7、7个等位基因和21、19、15种基因型,基因型分布符合Hardy-Weinberg平衡。3个基因座在湖南汉族人群的非父排除率和个体识别力分别为0．465、0．491、0．361和0．886、0．899、0．818。结论建立的3个miniSTR基因座扩增系统在DNA高度降解检材分析中具有较高的应用价值,并且在湖南汉族人群中具有较好的遗传多态性,可应用于个体识别和亲权鉴定。     

湖南汉族人群21个STR基因座的遗传多态性(英文)

目的调查湖南地区汉族人群21个STR基因座(D3S1358、D13S317、D7S820、D16S539、Penta E、D2S441、TPOX、TH01、D2S1338、CSF1PO、Penta D、D10S1248、D19S433、v WA、D21S11、D18S51、D6S1043、D8S1179、D5S818、D12S391和FGA)的遗传多态性。方法共采集560例湖南汉族健康无关个体血液样本,使用Chelex-100法提取DNA,应用AGCU EX22试剂盒及9700 PCR扩增仪进行复合扩增,扩增产物使用310遗传分析仪进行分离分析。结果共发现248个等位基因,等位基因频率分布在0.001~0.518。除Penta E(P=0.023)外,其余基因座的基因型分布均符合Hardy-Weinberg平衡。21个基因座的累积个人识别率、累积非父排除率、累积匹配率分别为0.999 999 999 999 999 999 999 999 8、0.999 999 998和1.36×10-25。结论 21个STR基因座在湖南汉族人群中呈高度多态性。本研究可为法医学个人识别及亲子鉴定提供有价值的数据及理论基础。     

中国成都地区汉族群体5个STR基因座的遗传多态性

采用PCR扩增,聚丙烯酰胺凝胶电泳分析技术,调查中国成都汉族群体DIS1656、D851179、D9S302、D185535及D195253等5个STR基因座的等位基因频率分布。D1S1656检出11个等位基因,35种基因型;DSS1179检出9个等位基因,32种基因型;D95302检出12个等位基因,50种基因型;D185535检出7个等位基因,20种基因型;D195253检出8个等位基因,28种基因型。5个STR基因座基因型频率分布符合Hardy-weinberg平衡（P＞0．05）。个人识别机率（DP）为0．92～0．98。分析了二代3口之家的遗传模式,证明5个STR基因座均符合孟德尔遗传规律。5个STR基因座PCR扩增采用同一条件,方法简单、快速、灵敏、重复性好,可用于法科学亲子鉴定和个人识别。     

Spanish population data on the loci D13S317, D7S820, and D16S539 generated using silver staining (SilverSTR III Multiplex).

A set of 212 samples from unrelated Spanish Caucasians living in Andalucia (southern Spain) were analyzed with a new commercially-available kit for multiplex amplification of 3 STR loci (D13S137, D7S820, and D16S539), manual denaturing polyacrylamide gel electrophoresis and silver staining. These three loci are of special interest for the forensic community since they are a part of the 13 CODIS-core STR loci. The results show that the loci D13S317 and D16S539 meet Hardy-Weinberg expectations (HWE), but the locus D7S820 did not meet HWE (p = 0.003). However, there was no detectable departures from independence (i.e., linkage disequilibrium) between any pair-wise combination of loci. The D7S820 data were further investigated. The excess homozygosity was due to an excess of D7S820 10, 10 homozygotes. To determine if the allele frequency data are meaningful and can be applied to forensic identity cases, the Spanish D7S820 allele frequency data were compared with four other Caucasian sample populations. The D7S820 allele frequencies were statistically similar; thus, the results support that the allele frequency data can be used reliably for estimating DNA profile frequencies.     

Swiss Caucasian population data for the STR loci D2S1338 and D19S433 using the AmpFISTR SGM plus PCR amplification kit

Allele and genotype frequencies for the ten STR loci D3S1358, VWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01, FGA were determined in a Swiss Caucasian population sample (n=206) using the AmpFISTR SGM Plus Amplification kit. Electrophoresis was carried out on an ABI PRISM CE 310 Genetic Analyzer instrument. Previously, allele frequencies were published for the 13 STR loci D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, THO1, TPOX, CSF1PO and D16S539 for the same samples (n=206) amplified with the AmpFISTR Profiler Plus and Cofiler PCR Amplification kits. Since the results for the eight loci D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, THO1, D16S539 shared between the AmpFISTR SGM Plus, Profiler Plus and Cofiler PCR Amplification kits already are published, only the allele frequencies for the two STR loci D2S1338 and D19S433 are reported in this paper. The two loci meet Hardy-Weinberg expectations. In addition, there is little evidence for association of alleles among the 15 loci (amplified with the Profiler, Cofiler, and SGM Plus amplification kits). The allelic frequency data can be used in forensic analyses to estimate the frequency of a multiple STR locus DNA profile in the Swiss population.     

Allele frequencies for nine STR loci in Ovambo population using AmpFlSTR Profiler Kit

Allele frequencies for the nine short tandem repeat (STR) loci D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, and D7S820 were investigated in 195 unrelated Ovambo (Bantus) population from Namibia. AmpFlSTR Profiler Kit was employed for amplification. For each locus, 6-19 alleles were observed. Comparison between Ovambo population data and that of other African populations was performed. AmpFlSTR Profiler detection system is a useful tool for individual identification in Ovambo population.     

Analysis of genotype frequencies and interlocus association for the PM, DQA1, and D1S80 loci in four populations

Allele frequencies of the LDLR, HBGG, GYPA, D7S8, GC, DQA1, and D1S80 loci are presented and genotypes are analyzed for each of four ethnic groups: African Americans (n = 200), US Caucasians (n = 200), US Hispanics (n = 200), and Japanese (n = 89). Hardy-Weinberg genotypic proportions were observed in all but two of the 28 population-locus tests undertaken. Those two instances are attributable to type I statistical error. Gametic equilibrium among loci is an assumption invoked for application of the product rule to utilize the discriminatory power from two or more loci simultaneously. Two statistical methods, a genotype matching statistic and log-linear modeling, were used to evaluate gametic disequilibrium. The match statistic, comparing observed to expected likelihood of genotypic identity for seven loci among pairs of individuals within the database, revealed only one statistically significant deviation among 20 tests. As expected, the probability of match was generally lowest in the test on all ethnic groups combined, indicating that allele frequencies differ among ethnic groups for some of the loci. This was confirmed with the statistic theta to measure ethnic stratification, in which about 0.10 of the genetic variation is apportioned among the four ethnic groups for four of the structural loci (LDLR, HBGG, GC, and DQA1), while for GYPA, D7S8, and D1S80, variation is more uniformly distributed among ethnic groups. Log-linear modeling was also applied to the five PM loci. The most parsimonious log-linear model included only three higher order terms: the two-way interactions of three of the PM loci with ethnic group. These three instances (LDLR, HBGG, and GC) indicated differences in allele frequencies between ethnic groups. No two or higher way interaction (disequilibrium) was observed among loci. In summary, the assumptions of Hardy-Weinberg and gametic equilibrium that facilitate the use of the five PM loci, DQA1 and D1S80 in forensic applications are consistent with the allele and genotype frequencies observed in these populations.     

成都汉族、甘肃东乡族群体D10S1432和D10S1213 位点的遗传多态性分析

目的本研究的目的是了解人类基因组中D10S1432及D10S1213两个STR位点在成都汉族和甘肃东乡族群体中的遗传多态性分布及两个群体之间的关系。方法采用PCR、聚丙烯酰胺凝胶电泳及银染技术,共调查了209例样本。结果在D10S1432位点上观察到5个等位基因,15种基因型。在D10S1213位点上观察到9个等位基因,31种基因型。两位点的基因型频率在调查的两个群体中的分布符合Hardy-Weinberg平衡定律（P>0.05）。经统计,D10S1432在这两个群体中的杂合度为0.664和0.737,个人识别几率为0.827和0.820。D10S1213的杂合度为0.664和0.657,个人识别几率为0.836和0.882。结论结果表明,D10S1432和D10S1213两个位点在法医学个人识别和亲子鉴定中有较高应用价值。     

Allelic distribution of four tetranucleotide repeat loci (D3S1358, D18S51, D19S253, and FGA) in a population from Porto (North Portugal)

Allele frequencies for four short tandem repeat loci were determined in a population sample from Porto (North Portugal), using the polymerase chain reaction (PCR), in order to investigate possible genetic differences between populations from the center and north of Portugal. After denaturing PAGE electrophoresis, nine alleles were identified for D3S1358 (n = 256), 13 alleles for D18S51 (n = 235), 10 alleles for D19S253 (n = 238), and 15 alleles for FGA (n = 181). No deviations from Hardy-Weinberg equilibrium were found. The allele frequencies observed are similar to those of the Portuguese population compared except for the D3S1358 system.     

PowerPlex~(TM) 16体系在中国人群中罕见等位基因及其类型

目的 分析PowerPlexTM 16体系基因座在中国人群中的罕见等位基因及其类型。方法 应用PCR-STR和DNA序列分析技术,对4650个无关个体在15个STR基因座中的罕见等位基因进行检测。结果 在PowerPlexTM16体系中的D7S820、D16S539、Penta E基因座,检测到2种类型的罕见等位基因,而TH01、D21S11、D5S818、D13S317、Penta D、D8S1179、TPOX、FGA基因座检测出1种类型。其等位基因频率均较低(0.215‰-7.097‰)。结论 超出ladder范围的罕见等位基因序列比相邻等位基因增加(或减少)1个或数个重复单位,因碱基的插入或缺失的罕见等位基因出现在两等位基因之间。