The maternal perspective for five Slovenian regions: The importance of regional sampling

<i>Background</i>: The Slovenian territory is geographically positioned between the Alps, Adriatic Sea, Pannonian basin and the Dinaric Mountains and, as such, has served as a passageway for various populations in different periods of time. Turbulent historic events and diverse geography of the region have produced a diverse contemporary population whose genetic analysis could provide insight into past demographic events.<i>Aim</i>: The aims of this study were to characterize the Slovenian mitochondrial gene pool at the micro-geographic level and to compare it with surrounding populations.<i>Subjects and methods</i>: A total of 402 individuals from five Slovenian regions were analysed in this study by typing HVR I, HVR II and coding region polymorphisms of mtDNA.<i>Results</i>: Analysis revealed 47 haplogroups and sub-haplogroups, the most common of which were H*, H1, J1c, T2 and U5a. Intra-population comparisons revealed a sharp gradient of the J1c haplogroup between Slovenian regions, with a peak frequency of 24.5% being observed in the population of the Littoral Region.<i>Conclusion</i>: The sharp gradient of the J1c haplogroup between Slovenian regions is in line with the archaeological horizon known as Impressed Ware culture and could, therefore, represent a genetic trace of the early Neolithic expansion route along the East Adriatic coastal region.