Vallone Peter M, Decker Amy E, Butler John M
Biotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8311, USA.
Forensic Sci Int. 2005 May 10;149(2-3):279-86. doi: 10.1016/j.forsciint.2004.07.014.
189 samples from 3 different U.S. sample groups Caucasian (74), African American (71) and Hispanic (44) were typed for 70 autosomal genetic markers. These 70 markers are bi-allelic (C/T) short nucleotide polymorphisms (SNPs). For each sample, the 70 SNP markers were typed in 11 unique 6-plexes and a single 4-plex PCR. A total of 10 of the 210 tests (70 loci x 3 populations) for Hardy-Weinberg equilibrium indicated a statistically significant result. In order to evaluate the minimum number of SNP loci needed to distinguish all 189 samples from one another, we ranked the loci according to their levels of observed heterozygosity and p-values obtained upon testing for Hardy-Weinberg equilibrium. The top 12 loci according to these ranking criteria were tabulated along with the number of unique genotypes observed when combining subsequent SNP markers. The 12 selected SNPs possessed an observed heterozygosity of >0.45 in all three populations examined and thus would be expected to exhibit more differences between samples. All of the 189 samples in this study were individualized with a subset of 12 SNP loci. However, it is likely that the addition of more than 12 SNP loci will be required to resolve larger sets of unrelated individuals from one another. By way of comparison, in these same 189 individuals all but one pair is resolved from one another with three of the traditional short tandem repeat (STR) loci possessing the highest heterozygosity values (D2S1338, D18S51, and FGA) run with the Identifiler kit. The final pair of unrelated samples could be resolved with the combination of 4 STR loci: D2S1338, D18S51, FGA, and VWA.
对来自美国3个不同样本组（白种人74例、非裔美国人71例和西班牙裔44例）的189个样本进行了70个常染色体遗传标记的分型。这70个标记为双等位基因（C/T）短核苷酸多态性（SNP）。对于每个样本，70个SNP标记通过11个独特的6重PCR体系和1个4重PCR进行分型。在210次检测（70个位点×3个群体）中，共有10次哈迪-温伯格平衡检测结果具有统计学意义。为了评估区分所有189个样本所需的最少SNP位点数量，我们根据观察到的杂合度水平和哈迪-温伯格平衡检测时获得的p值对位点进行排序。根据这些排序标准列出了前12个位点，以及组合后续SNP标记时观察到的独特基因型数量。在所有检测的3个群体中，所选的12个SNP的观察杂合度均>0.45，因此预计样本之间会表现出更多差异。本研究中的所有189个样本都通过12个SNP位点的子集进行了个体化区分。然而，可能需要增加超过12个SNP位点才能区分更多的无关个体。相比之下，在这189个个体中，除了一对个体外，其余个体都通过使用Identifiler试剂盒检测3个具有最高杂合度值的传统短串联重复序列（STR）位点（D2S1338、D18S51和FGA）得以区分。最后一对无关样本可以通过4个STR位点（D2S1338、D18S51、FGA和VWA）的组合来区分。
