Resolving the most common mtDNA control region haplotype by massively parallel sequencing: a pilot study in an Italian population sample.

The high mutation rate of mitochondrial (mt)DNA, its lack of recombination, its high abundance in the cell and its greater resistance to environmental stress make the analyses of this molecule the most promising choice in forensic genetics when nuclear markers fail to give reliable results. The control region (CR) shows the highest variability and is therefore routinely typed in forensic studies. Coding region data are currently used almost exclusively for a phylogenetic assignment of mtDNA haplotypes and in population genetic studies. The extended analysis of the mitochondrial genome covering also the coding region is however also useful in forensic applications, e.g. to further differentiate identical CR haplotypes. The most frequent western Eurasian mtDNA CR haplotype 16519C-263G-315.1C (with respect to the rCRS) has been observed in various sub-haplogroups of haplogroup R0 (Brandstätter et al., 2008). In the current study 29 samples that displayed this haplotype were selected from a larger Italian population study (Boattini et al., 2013) and sequenced for their coding region by massively parallel sequencing as previously described (Parson et al., 2013). The obtained complete mtGenome haplotypes were assigned to their established sub-haplogroups and interpreted with respect to their phylogenetic and geographic background. This study clearly demonstrates the benefit of full mtGenomes to increase the resolution of mtDNA sequencing in forensic genetics.