Genetic polymorphisms of 66 InDel loci in the Chinese Han population

Insertion/deletion polymorphism (InDel) genetic markers refer to insertion or deletion of DNA fragments into genomic DNA, which have advantages in the identification of degraded samples. In this study, we independently screened 66 highly polymorphic InDel markers from the dbSNP database to establish a multiplex PCR system for forensic DNA identification using next-generation sequencing system (66-plex InDels). We assessed the population genetic data among 251 Chinese Han population using this system and evaluated their potential forensic application. The results showed that all 66 InDel loci conformed to the Hardy-Weinberg equilibrium (P>0.000 758), and all the pairwise InDel loci were in linkage equilibrium after Bonferroni correction. The mean observed heterozygosity (Ho) was 0.482, the mean expected heterozygosity (He) was 0.483,the mean discrimination power (DP) was 0.612, the mean polymorphism information content (PIC) was 0.365, the total discrimination power (TDP) reached 0.999 999 999 999 999 999 999 999 999 428 18. The cumulative power of exclusion for 66 InDel loci was 0.999 739 in duo cases (CPE_duo) and was 0.999 999 999 417 in trios cases (CPE_trio). The results show that the 66 InDel loci have high genetic polymorphisms in the Chinese Han population and can be used independently for forensic DNA identification and paternity testing.