Forensically relevant phylogeographic evaluation of mitogenome variation in the Basque Country

The Basque Country has been the focus of population (genetic) and evolutionary studies for decades, as it represents an interesting evolutionary feature: it is the only European country where a non-Indo-European language is still spoken today and, for which there are no known living or extinct relatives. Early studies that were based on anatomical and serological methods, along with subsequent molecular genetic investigations, contain controversial interpretations of their data. Additionally, the analysis of mitochondrial DNA, which is maternally inherited and thus suitable for the examination of the maternal phylogeny of the population, was the focus of some studies. Early mtDNA studies were however restricted to the information provided by the control region or its hypervariable segments only. These are known to harbour little phylogenetic information, particularly for haplogroup H that is dominant in Westeurasian populations including the Basques. Later studies analysed complete mitogenome sequences. Their information content is however limited, either because the number of samples was low, or because these studies only considered particular haplogroups. In this study we present the full mitogenome sequences of 178 autochthonous Basque individuals that were carefully selected based on their familial descent and discuss the observed phylogenetic signals in the light of earlier published findings. We confirm the presence of Basque-specific mtDNA lineages and extend the knowledge of these lineages by providing data on their distribution in comparison to other Basque and non-Basque populations. This dataset improves our understanding of the Basque mtDNA phylogeny and serves as a high-quality dataset that is provided via EMPOP for forensic genetic purposes.