Autosomal short tandem repeat genetic variation of the Basques in Spain

AIM To examine population genetic structure and hypotheses of the origin of the modern Basque population in Spain using autosomal short tandem repeat (STR) data from individuals living in 27 mountain villages in the provinces of Alava, Vizcaya, Guipuzcoa, and Navarre, by comparing Basque autosomal STR variation with that of neighboring populations in Europe, as well as proposed ancestral populations in North Africa and the Caucasus. METHODS Allele frequencies for 9 autosomal STR loci (D3S1358, D5S818, D7S820, D8S1179, D13S317, D18S51, D21S11, FGA, and vWA) and several population genetic parameters were determined for the 4 provinces in the Basque region of Spain (n=377). Heterozygosity within the Basque population was measured using a locus-by-locus analysis of molecular variance. Relationships between the Basques and other populations were examined using a multidimensional scaling (MDS) plot of Shriver's DSW distance matrix. RESULTS Heterozygosity levels in the Basque provinces were on the low end of the European distribution (0.805-0.812). The MDS plot of genetic distances revealed that the Basques differed from both the Caucasian and North African populations with respect to autosomal STR variation. CONCLUSIONS Autosomal STR analysis does not support the hypotheses of a recent common ancestor between the Basques and populations either from the Caucasus or North Africa.