High frequency of mitochondrial haplogroups H and H2 in medieval individuals from the Cathedral of Santa María (Basque Country). Their contribution to the study of inflammatory arthropathies

•High frequency of mtDNA haplogroup H in a medieval population of the Basque Country.•A relationship between mtDNA sub-haplogroup H2 and Spondyloarthropathies.•Paleopathology and aDNA analysis: an approach to understand the arthropathies.•The Cathedral of Santa María (Vitoria-Gasteiz): a case-study for medieval populations.