Forensic parameters and genetic structure analysis of 30 autosomal InDels of the population in Freetown, Sierra Leone

Insights into AIM-InDel diversities in Yunnan Miao and Hani ethnic groups of China for forensic and population genetic purposes

Background

Ancestry informative markers are regarded as useful tools for inferring the ancestral information of an individual, which have been widely used in the criminal investigations and population genetic studies. Previously, a multiplex amplification panel containing 39 AIM-InDel loci was constructed. This study aims to investigate the genetic polymorphisms of these 39 AIM-InDel loci in Yunnan Hani and Miao ethnic groups, and to uncover their genetic affinities with reference populations based on the AIM-InDel markers.

Materials and methods

In this research, 39 AIM-InDel profiles of 203 unrelated Miao individuals and 203 unrelated Hani individuals in Yunnan province of China were acquired. Additionally, we evaluated the genetic polymorphisms of 39 InDel loci in Yunnan Miao and Hani groups. Moreover, the genetic relationships among Yunnan Miao, Hani and reference populations were also clarified based on Nei’s genetic distances, pairwise fixation indexes, principal component analyses, phylogenetic analyses, and STRUCTURE analyses.

Results

Genetic diversity analyses demonstrated that these InDel loci showed varying degrees of genetic polymorphisms, and could be utilized in forensic identifications in Yunnan Miao and Hani groups. The results of principal component analyses, phylogenetic analyses and Structure analyses revealed that Yunnan Miao and Hani groups had closer genetic relationships with East Asian populations, especially with the populations from Southern China. This research enriched the genetic data of Chinese ethnic minority, and provided ancestral information of Yunnan Miao and Hani groups from the perspective of population genetics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41065-022-00238-9.

Forensic characteristics and genetic structure of 18 autosomal STR loci in the Sierra Leone population

Population genetic analysis is of vital importance for personal identification and paternity testing in forensic science. However, the forensic characteristics of autosomal short tandem repeat (STR) loci in the Sierra Leone population have not been reported yet to the best of our knowledge. In this study, 528 unrelated individuals (256 males and 272 females) in Sierra Leone, West Africa, were genotyped using the DNA Typer19™ kit; forensic parameters and genetic relationships with 32 populations around the world were analyzed. A total of 239 alleles were detected, with corresponding allele frequencies ranged from 0.0009 to 0.4545. The cumulative power of discrimination (CPD) value of the 18 STR loci was 0.9999999999999999999999697; the cumulative probability of exclusion for duos (CPE _duos) and exclusion for trios (CPE _trios) were 0.99999343 and 0.9999999895, respectively. Genetic comparisons showed that the Sierra Leone population has a closer genetic relationship with the Bantu-speaking populations in Sub-Saharan Africa.