HLA-DQA1 in autochthonous Basques: description of a genocline for the DQA1*0201 allele in Europe.

A total of 250 autochthonous Basque individuals were tested in the HLA-DQA1 system, and the allele frequency distribution found was significantly different from that of any other European population. The differences centre mainly on the alleles DQA1*0201 and DQA1*0501: for the former the Basques have the highest frequency described anywhere in the world (f = 0.210) and for the latter they have the lowest frequency in Europe (f = 0.204). For the allele DQA1*0201 a genocline is also described in Europe with the Basques and Finno-Ugric populations basically at the extremes. The genocline reflects the isolation of the Basque population since prehistoric times, and supports existing linguistic, archaeological and genetic data.