Forensic application research of kinship identification disclosed by genetic polymorphisms of 150 loci in three panels.

Insertion/deletion (InDel) polymorphisms show promising applications in the field of forensic genetics, such as ancestry inference and complex kinship identification. In the present study, we investigated the genetic polymorphisms and forensic parameters of Chinese Baoan group based on three panels, and explored the genetic connections between the Baoan group and 26 intercontinental reference populations. Based on simulated genotyping data constructed from allele frequencies of 150 loci, the study utilized the likelihood ratio (LR) method and identical by state (IBS) method to assess the system efficacy of different panels and identification of complex kinships with the increase in the number of genetic markers. The results indicated that the 150 loci were highly polymorphic in the Baoan group, and the Baoan group was genetically closer to the reference East Asian populations. The identification efficacy of different kinships based on the 150 loci was greater than that of single panel alone or a combination of any two panels, which suggested that both the increase in the number of genetic markers and the joint analysis of different panels could enhance the system efficacy of kinship identification. The system efficacy for the identifications of different kinships based on the combination of 150 loci were 1 and 0.9900 in parent-child and full-sibling pairs, respectively (LR > 10,000, LR < 0.0001); 0.8595, 0.8790, and 0.8615 in half-sibling, grandparent-grandchild, and uncle-nephew pairs, respectively (LR > 10, LR < 0.1); 0.3170 in first cousin pairs (LR > 10, LR < 0.1).