Molecular polymorphisms of the ABO locus as informative markers of ancestry in Central Argentina.

Objectives: The aim of this study was to investigate the distribution of molecular polymorphisms of the ABO gene in four population samples from the province of Córdoba, in Central Argentina, and to compare them with other worldwide populations.

Methods: A total of 110 buccal swab samples from autochthonous individuals of Córdoba were typified. Molecular characterization of the allelic variants was performed by the analysis of exons 6 and 7 of the ABO gene using PCR-RFLP analysis. Additionally, the Native American AIM O1v542 was characterized by direct sequencing.

Results: The four Córdoba populations did not show significant geographic structure, although the frequency of the O1v542 haplotype, detected in all the populations studied, ranged from 0.019 to 0.222. The principal component analysis based on O allele distribution showed that the populations from Córdoba clustered close to the admixed populations of Santiago and Mexico City, and at intermediate distances between European and Native American populations, while being distant from the African population.

Conclusions: The results demonstrate that the analysis of the ABO system constitutes a useful tool for the study of the genetic structure and evolutionary history of human populations, reflecting accurately the relative contribution of parental continental contribution to the gene pool of admixed populations.