Evaluating African-Derived mtDNA Haplotype Diversity Via Independent Sample Collections

Abstract

ABSTRACTSince the sample sizes for forensic cases, as well as studies of African ethnic groups, are usually low, and independent samples are rare, it has been difficult to determine whether small samples contain an accurate representation of a sampled population. In this study, two independent samples of the Bamileke had similar values with regard to standard and molecular diversity indices and selective neutrality. The two Fulbe samples were also similar, but they differed with respect to selective neutrality values. In both ethnic groups, shared haplotypes were present at low frequencies. However, the Fulbe had fewer exclusive matches with outside ethnic groups compared to the Bamileke. Nevertheless, in both ethnic groups, within-group matches were more common than matches to any other Cameroonian ethnic group. Only a small percentage of the observed mtDNA haplotypes have the potential for being ethnic and/or region specific. To assess this potential, sample sizes will have to be orders of magnitude larger in order to observe significant numbers of those relatively rare haplotypes. However, as database size is increased, haplotype sharing will correspondingly increase; and many haplotypes that are common in a single ethnic group will also be found in multiple ethnic groups.