Forensic Genetics Laboratory, School of Health and Life Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil; Technical Scientific Section, Federal Police Department in Rio Grande do Sul State, Porto Alegre, RS, Brazil; National Institute of Science and Technology - Forensic Science, Porto Alegre, RS, Brazil.
Forensic Genetics Laboratory, School of Health and Life Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Forensic Sci Int Genet. 2022 Mar;57:102650. doi: 10.1016/j.fsigen.2021.102650. Epub 2021 Dec 21.
The advent of massively parallel sequencing (MPS) applications focused on the generation of forensic-quality full mitochondrial genome sequences led to a popularization of the technique on a global scale. However, the lack of forensic-graded population databases has refrained a wider adoption of full genome sequences as the industry standard, despite its better discrimination capacity of individual maternal lineages.
This work describes a forensic-oriented full mtDNA genome database comprised of 480 samples from a Southern Brazilian population.
A collection of mitochondrial sequences were obtained from low-pass, full genome DNA sequencing results. The complete sample set was evaluated regarding haplotype composition and distribution. Summary statistics and forensic parameters were calculated and are presented for the database, with detailed information concerning the impact of removing genetic information in the form of specific variants or increasingly larger genomic regions. Interpopulational analysis comparing haplotypical diversity in Brazilian and 26 worldwide populations was also performed. The association between mitochondrial genetic variability and phenotypic diversity was also evaluated in populations, with self-declared ancestry and three distinct phenotypic pigmentation traits (eyes, skin and hair colors) as parameters.
The presented database can be used to evaluate mitochondrial-related genetic evidence, providing LR values of up to 20,465 for unobserved haplotypes. Haplotype distribution in Southern Brazil seems to be different than the remaining of the country, with a larger contribution of maternal lines with European origin. Despite association can be found between lighter and darker phenotypes or self-declared ancestry and haplotype distribution, prediction models cannot be reliably proposed due to the admixed nature of the Brazilian population.
The proposed database provides a basis for statistical calculation and frequency estimation of full mitochondrial genomes, and can be part of an integrated, representative, national database comprising most of the genetic diversity of maternal lineages in the country.
大规模平行测序（MPS）应用的出现主要集中在生成法医质量的完整线粒体基因组序列上，这导致该技术在全球范围内得到普及。然而，由于缺乏法医级别的群体数据库，尽管全基因组序列在个体母系谱系的辨别能力上更好，但它仍未能被更广泛地采用为行业标准。
本研究描述了一个由来自巴西南部的 480 个样本组成的面向法医的全 mtDNA 基因组数据库。
从低通全基因组 DNA 测序结果中获得了一系列线粒体序列。对完整样本集进行了单倍型组成和分布评估。计算并呈现了数据库的摘要统计和法医参数，并详细介绍了去除特定变体或更大基因组区域遗传信息的影响。还比较了巴西和 26 个世界人口群体的单倍型多样性的种间分析。还评估了线粒体遗传变异性与表型多样性之间的关联，以自我宣称的祖先和三个不同的表型色素特征（眼睛、皮肤和头发颜色）为参数。
本研究提出的数据库可用于评估与线粒体相关的遗传证据，提供高达 20,465 的未观察到单倍型的 LR 值。巴西南部的单倍型分布似乎与该国其他地区不同，具有更多欧洲起源的母系贡献。尽管可以发现较浅和较深表型或自我宣称的祖先与单倍型分布之间存在关联，但由于巴西人口的混合性质，无法可靠地提出预测模型。
本研究提出的数据库为全线粒体基因组的统计计算和频率估计提供了基础，并可以作为一个综合的、有代表性的、包含该国大多数母系遗传多样性的全国性数据库的一部分。
