Brief communication: Molecular characterization of O alleles at the ABO locus in Chilean Aymara and Huilliche Indians

A molecular characterization of alleles O¹, O^1variant (O^1v), and the mutation G542A of the ABO blood group was performed in two Amerindian populations of Chile, the Aymara (n = 84) and the Huilliche (n = 75). In addition, a sample of 82 individuals of Santiago belonging to the mixed Chilean population was typed for comparative purposes. The polymorphisms which allow for molecular differentiation of different alleles of the O blood group were studied in genomic DNA. The mutations G188, G261-, G542A, T646A, and C771T, described for alleles O¹, O^1v, and G542A, were determined using the PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) technique. All individuals studied were group O homozygotes for the deletion G261-, which defines the O¹ alleles. Results obtained indicate that allele O^1v exhibits frequencies of 0.65, 0.81, and 0.60 in Aymara, Huilliche, and Santiago populations, respectively. The frequencies of allele O^1(G542a) were 0.119, 0.113, and 0.079 in the same populations. Frequencies for alleles O¹ and O^1v obtained in the Chilean populations studied concur with the results obtained by other authors, respecting the greater frequency of allele O^1v as well as with its heterogeneous distribution in aboriginal South American populations. In Chilean populations, Allele G542A exhibits lower frequencies than those described for indigenous populations from Brazil and may be used as an Amerind admixture marker.