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.     

Population data for Southern Spain and Canary Islands of HLADQA1, PM and D1S80 loci

Allele frequencies for seven polymerase chain reaction (PCR)-based DNA genetic markers in two Spanish populations (Southern Spain and Canary Islands), were determined and compared. The loci analysed were HLADQA1, LDLR, GYPA, HBGG, D7S8,Gc, and D1S80.     

The distribution of D1S80 and VWA alleles in a Karen population from Northern Thailand

The DIS80 and VWA loci were studied in a Karen population from Northern Thailand by the polymerase chain reaction and polyacrylamide gel electrophoresis. Twelve DIS80 and six VWA alleles were found. No deviations from the Hardy-Weinberg and linkage equilibrium were observed. The power of exclusion (PE) from the analysis of the DIS80 and VWA locus is 0.67 and 0.45, respectively, the power of discrimination (PD) is 0.95 and 0.85, respectively, with a combined PD of 0.99 and PE of 0.82.     

Population frequency for the short tandem repeat loci D18S849, D3S1744, and D12S1090 in Caucasian-Mestizo and African descent populations of Colombia

Blood samples from 489 unrelated Caucasian Mestizo and 252 individuals of African descent in Colombia were amplified and typed for three short tandem repeat (STR) markers (D12S1090, D3S1744, and D18S849). All markers conformed to Hardy-Weinberg equilibrium expectations in both populations studied. In addition, heterozygosity, mean exclusion chance, polymorphism information content, discrimination power, and the assumption of independence within and between loci were determined. The mean exclusion chance for all three STR markers is 0.9750 in the Caucasian Mestizo population and 0.9731 in the African Colombian Population. The discrimination power is 0.999925 and 0.999911 in the Caucasian Mestizo and African Colombian respectively.     

Spanish population data on seven loci: D1S80, D17S5, HUMTH01, HUMVWA,ACTBP2, D21S11 and HLA-DQA1

Blood samples from 120 Spanish Caucasian individuals were amplified and typed by electrophoresis at six loci, and by reverse dot-blot hybridization at one locus. Results demonstrate the assumption of independence within and between the seven loci analyzed. Therefore, a Spanish population database has been established and statistical analysis shows that a high degree of discrimination can be obtained when all seven (or fewer) loci are used to characterize forensic biological evidence.     

Polymorphism of LDLR, GYPA, HBGG, D7S8, GC, HLA-DQA1, Ig-JH, D17S30, ApoB and D1S80 loci in northwestern Russians

Allele frequencies for polymarker, HLA-DQA1, Ig-JH, D17S30, ApoB and D1S80 loci and population genetic parameters were obtained from a sample of 501 unrelated individuals born in the northwestern Federal Region of Russia.