Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
J Forensic Sci. 2021 Sep;66(5):1637-1646. doi: 10.1111/1556-4029.14724. Epub 2021 Apr 22.
For the past two to three decades, forensic DNA evidence has been analyzed with a limited number of short tandem repeats (STRs), and these STRs are usually assumed to be independent for statistical calculations. With the development and implementation of the MPS technologies, more autosomal markers, both single nucleotide polymorphisms (SNPs) and STRs, can be analyzed. A number of these markers are physically very close to each other, and it may not be appropriate to assume all these markers are genetically unlinked or in linkage equilibrium. In this study, publicly accessible genomic data from five representative populations were used to evaluate the genetic linkage and linkage disequilibrium (LD) between autosomal markers represented in six major commercial panels (in total, 362 markers). Among the 3041 syntenic marker pairs, 1524 pairs had sex-average genetic distances <50 cM, and thus, these marker pairs can be considered as genetically linked. Among the 143 marker pairs with physical distances <1 Mb, 19 LD haplotype blocks (comprising 39 SNPs in total) were detected for at least one of the tested populations. Statistical methods for interpreting linked markers and/or markers in LD were suggested for various case scenarios.
在过去的二三十年中，法医 DNA 证据一直使用有限数量的短串联重复序列 (STRs) 进行分析，并且这些 STRs 通常被假定为独立的用于统计计算。随着 MPS 技术的发展和实施，可以分析更多的常染色体标记物，包括单核苷酸多态性 (SNPs) 和 STRs。这些标记物中有许多在物理上非常接近，因此假设所有这些标记物在遗传上不连锁或处于连锁平衡状态可能并不合适。在这项研究中，使用来自五个代表性人群的公开可得的基因组数据来评估六个主要商业面板中代表的常染色体标记物之间的遗传连锁和连锁不平衡 (LD)（总共 362 个标记物）。在 3041 对同源标记物对中，有 1524 对具有<50cM 的性别平均遗传距离，因此可以认为这些标记物对在遗传上是连锁的。在 143 对物理距离<1Mb 的标记物对中，对于至少一个测试人群检测到了 19 个 LD 单倍型块（总共包含 39 个 SNP）。对于各种案例情况，建议了用于解释连锁标记物和/或处于 LD 的标记物的统计方法。
