Forensic efficiency and genetic variation of 30 InDels in Vietnamese and Nigerian populations

Insertion/deletion polymorphisms (InDels) are ubiquitous diallelic genetic markers that have drawn increasing attention from forensic researchers. Here, we investigated 30 InDel loci in Vietnamese and Nigerian populations and evaluated their usefulness in forensic genetics. The polymorphic information content of these populations ranged, respectively, from 0.164 to 0.375 and from 0.090 to 0.375 across loci. After Bonferroni correction, no significant deviation from Hardy-Weinberg equilibrium was found, except for HLD97 in the Nigerian population. The cumulative power of exclusion for all 30 loci in the Vietnamese and Nigerian populations was 0.9870 and 0.9676, respectively, indicating that this InDel set is not suitable for paternity testing in these populations, but could be included as a supplement. For the Vietnamese and the Nigerian populations, the mean observed heterozygosity was 0.5917 and 0.6268, and the combined discrimination power of the 30 loci was 0.9999999999767 and 0.9999999999603, respectively. These findings indicated that these InDels may be suitable for personal forensic identification in the studied populations. The results of D(A) distance, phylogenetic tree, principal component, and cluster analyses were consistent and indicated a clear pattern of regional distribution. Moreover, the Vietnamese population was shown to have close genetic relationships with the Guangdong Han and Shanghai Han populations.