Klitz W, Reynolds R, Chen J, Erlich H A
School of Public Health, University of California, Berkeley 94720, USA.
J Forensic Sci. 2000 Sep;45(5):1009-15.
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.
呈现了低密度脂蛋白受体（LDLR）、血红蛋白γ基因（HBGG）、血型糖蛋白A（GYPA）、D7S8、维生素D结合蛋白（GC）、DQA1和D1S80基因座的等位基因频率，并对四个种族群体进行了基因型分析：非裔美国人（n = 200）、美国白种人（n = 200）、美国西班牙裔（n = 200）和日本人（n = 89）。在所进行的28次群体 - 基因座测试中，除了两次之外，其余所有测试均观察到了哈迪 - 温伯格基因型比例。这两个例外情况可归因于I型统计误差。基因座间的配子平衡是应用乘积法则以同时利用两个或更多基因座的鉴别力时所采用的一个假设。使用了两种统计方法，即基因型匹配统计和对数线性建模来评估配子不平衡。匹配统计比较了数据库中个体对之间七个基因座的观察到的与预期的基因型相同的可能性，在20次测试中仅发现一个具有统计学意义的偏差。正如预期的那样，在所有种族群体合并的测试中，匹配概率通常最低，这表明某些基因座的等位基因频率在不同种族群体之间存在差异。通过用于测量种族分层的统计量theta证实了这一点，其中对于四个结构基因座（LDLR、HBGG、GC和DQA1），约0.10的遗传变异分配给四个种族群体，而对于GYPA、D7S8和D1S80，变异在种族群体之间分布更为均匀。对数线性建模也应用于五个多态性标记（PM）基因座。最简约的对数线性模型仅包括三个高阶项：三个PM基因座与种族群体的双向相互作用。这三个实例（LDLR、HBGG和GC）表明不同种族群体之间等位基因频率存在差异。在基因座之间未观察到二阶或更高阶的相互作用（不平衡）。总之，促进在法医应用中使用五个PM基因座、DQA1和D1S80的哈迪 - 温伯格平衡和配子平衡假设与在这些群体中观察到的等位基因和基因型频率一致。
