HLA-DQA1 allele and genotype frequencies in a northern Italian population.

HLA-DQA1 typing of 227 randomly selected Northern Italian people by the use of polymerase chain reaction are reported. The combined use of commercial Amplitype HLA-DQalpha system and four sequence-specific oligonucleotide probes allows the definition of 8 alleles and 36 genotypes, arranged according to World Health Organisation nomenclature. Seven of these genotypes are not observed among the analyzed samples. Allele frequencies range from 1.5 to 35.7% and genotype observations do not deviate significantly from Hardy-Weinberg equilibrium; observed heterozygosity is 0.8238 with an allelic diversity value of 0.79 and the power of discrimination is 0.925. Our Italian population sample shows differences from other Caucasian samples both for allele and genotype frequencies. This locus typing for the 8 defined alleles provides a rapid and sensitive method in individual identification and paternity investigation.     

Distribution of the HLA-DQA1 and polymarker alleles in the Basque population of Spain

HLA-DQA1 and polymarker (LDLR, GYPA, HBGG, D7S8, and GC) genotypic and allelic frequencies are determined for a population sample of 102 unrelated Basque individuals using PCR-based methodology. All six loci met Hardy-Weinberg expectations in at least two of the three analyses performed (HLA-DQA1 failed to meet Hardy-Weinberg requirements in the heterozygote deficiency test). Three linkage analysis programs (GDA, GENEPOP and LINKDOS) detected possible linkage disequilibrium between LDLR and HBGG and results from one (GDA) indicated a possible non-random association between HBGG and HLA-DQA1 as well. Allelic data for the six loci are compared to that previously established for other populations (18 for polymarker alone, 16 for polymarker plus HLA-DQA1) to determine homogeneity between the Basque sample and these groups. According to the results of G-tests based on these loci, the Tadjik, a nomadic Caucasian group from western Asia, and the Basque residents are the only sample populations surveyed that are homogenous with the Basque sample. Phylogenetic analysis places the Basque sample correctly within the Caucasian cluster.     

Allelic distribution of nine short tandem repeat (STR), HLA-DQA1, and polymarker loci in an Omani sample population

Allele frequency distributions of nine short tandem repeat (STR) loci, D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D7S820, and D13S317, HLA-DQA1 and polymarker (PM) loci were studied in a sample population from Sultanate of Oman, Middle East. Blood samples were collected from 162 unrelated individuals. For all STR, HLA-DQA1 and PM loci, no deviations from Hardy-Weinberg equilibrium, based on the exact test, were observed. The most discriminating loci were D18S51 (PD=0.966) and FGA (PD=0.964), while the least informative locus is GYPA (PD=0.585). The allele frequency data may be useful in forensic case work.     

Gene and genotype frequencies for HLA-DQA1 in Caucasians and Mulattoes in Brazil.

Gene and genotype frequencies of the HLA-DQA1 locus were determined in a sample of 197 unrelated individuals (144 Caucasians and 53 Mulattoes), living in the city of S?o Paulo, Brazil. The Mulatto group consisted of mixed individuals who presented at least one negroid physical characteristic or declared themselves to be of mixed ancestry. A total of six different alleles were identified with frequencies ranging from 0.087 to 0.316 in the Caucasian population and from 0.066 to 0.330 in the Mulatto population. We observed an increased frequency of allele 1.2 among Mulattoes in relation to Caucasians. The sample heterozygote frequency was 0.722 among Caucasians and 0.736 among Mullatoes. No significant deviations from Hardy-Weinberg equilibrium were found either in the Caucasian or in the Brazilian Mullato population samples.     

AMPFlSTR Identifiler STR allele frequencies in Tanzania, Africa

POPULATION:  Identifiler—Employees and students of Muhimibili University College of Health Sciences in Dar es Salaam representing 19 widely distributed administrative districts and 42 tribes within the country.     

Swiss allele frequencies and haplotypes of 7 Y-specific STRs

In view of application to personal identification and paternal analysis, the allele distribution of the loci DYS 19, DYS389 I and II, DYS390, DYS391, DYS392, and DYS393 were determined in a sample of 126 unrelated males from the area of Bern (Switzerland). The 7 Y-STR loci were coamplified in a total of two multiplex reactions using fluorescently-labeled primers. PCR products were separated and detected on a capillary electrophoresis ABI Prism 310 instrument. All loci were polymorphic and the allele distributions are similar to other caucasian data.     

Four X-chromosomal STRs and their allele frequencies in a Chinese population

X-chromosomal markers are particularly useful for solving complex problems relating to kinship and deficiency paternity analysis. In the present study, population genetics data of four X-chromosomal short tandem repeats (STRs) DXS8378, HPRTB, DXS7423 and DXS7132 were obtained by analyzing 500 unrelated Chinese individuals (250 males and 250 females). Population genetics data obtained from the Chinese were compared with those of the Asian and European population. Mutations in X-chromosomal markers were analyzed based on a total of 61 proven father-child and 45 proven mother-child pairs.     

Estimating allele frequencies of hypervariable DNA systems.

Several polymorphisms of human DNA have been shown to be hypervariable due to the recurrence of a variable number of tandem repeats (VNTRs) in the lengths of allelic restriction fragments. The recurrence of allelic variants in this novel class of polymorphisms seems to comply well with a model of continuous random variables. Based on this assumption, we have compiled some simple algorithms for classification of continuous data and estimation of classes of relative frequencies and have implemented these routines for the management of databases storing hypervariable single locus DNA genetic systems. The algorithms are compiled in BASIC language and can be incorporated in task-oriented computer programs. Three procedures are discussed, based in turn on: (a) using predetermined, arbitrary classes; (b) point estimations of frequencies for single fragments using error measurements associated with the kilobase value assignment; (c) estimates of phenotype frequencies according to error measurements. Error measurements are obtained from a statistic of values pertaining to several restriction fragments (genomic controls) repeatedly tested in different experiments. Problems related to these approaches are discussed.     

STR等位基因频率对父权指数的影响

目的观察中国汉族不同人群STR等位基因频率对联合父权指数(CPI)的影响。方法随机取108例13个CODIS基因座分型结果不排除父权关系的三联体案和二联体案,用5个不同地区人群的等位基因频率计算CPI值。结果三联体案的CPI值在2077.63～50897711626.46之间,同一案例的最大CPI与最小值CPI之比大于100者有20例(19.52%);二联体案的CPI值在25.12～2998685141之间,同一案例的最大CPI与最小值CPI之比大于100者有13例(12.04%)。结论不同人群等位基因频率计算CODIS基因座所得的CPI值在部分亲权鉴定案中有很大的差异。为了防止等位基因频率不确定性带来的误差,建议在亲权鉴定中用保守法计算CPI值。     

Allelic frequencies for the HLA-DQA1, D1S80, HUMTHO1, HUMTPOX, HUMCSF1PO and HUMVWA loci in Cantabria (middle north Spain)

Allele frequencies for six DNA polymorphisms have been studied in a population sample from Cantabria (middle north Spain) using the polymerase chain reaction. The HLA-DQA1 locus was analyzed by the reverse dot-blot technique and the other five by polyacrylamide gel electrophoresis followed by silver staining. Six alleles were found for HLA-DQA1. 15 alleles for D1S80, 6 alleles for HUMTHO1 and HUMCSF1PO, 7 for HUMTPOX and 8 alleles for HUMVWA. The 21 repeat allele in HUMVWA had not previously been reported in a Spanish population. The genotype distributions met Hardy-Weinberg expectations for all the systems and some statistical parameters of forensic interest were calculated. Comparisons with other populations revealed significant differences for HLA-DQA1, HUMVWA and HUMTHO1, with interracial differences being more pronounced than between Spanish populations. The HUMVWA system showed the highest forensic efficiency of the six polymorphisms studied.     

新Y-STR基因座DYS709在汉族人群中的遗传多态性调查

目的筛选新的Y-STR基因座,调查其在汉族人群中的等位基因频率分布,评价其在法医学及其它方面的应用价值。方法在Y染色体基因组DNA中查找候选基因座,在重复顺序两端设计引物,PCR扩增后用银染法显示结果。结果一个重复单位为CTTT的Y-STR基因座DYS709被发现。在102例汉族无关男性个体血样中共检出了7个等位基因。基因多样性为0.7063,个人识别能力(PD)和非父排除率(PE)均为0.7063。结论新筛选到的DYS709具有较高的遗传多态性,在法医学及人类遗传学方面具有应用价值。     

Regional Italian allele frequencies at nine short tandem repeat loci

An Italian population study was performed on the loci D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, D7S820 and a portion of the X-Y homologous gene Amelogenin for gender determination using the AmpFlSTR Profiler kit (PE Biosystems, Foster city, CA). This study was done on a population of 618 unrelated Italian individuals from 18 regions in Italy (except for Valle d'Aosta and Sardinia) to determine allele frequencies for each STR locus, and to evaluate STR technology for developing an Italian Offender DNA database.