Interaction between ABO and haptoglobin systems in a Chilean population of mixed ancestry

Abstract

In order to investigate the association between ABO blood groups and serum haptoglobin (Hp), we typed Hp and ABO blood groups in 288 children, who were selected at random among those who began their primary school in 1973 in the Northern Metropolitan area of Santiago, Chile. This region has an Amerindian component of 40% and a Caucasian component (principally Spanish) of 60%. Our results are in contrast with previous studies which have reported that Hp*1 varied among ABO groups in the following manner, O < A < B < AB, and where Hp*1 was significantly lower in group O individuals. In the present study, the order was A < O » B < AB. We found more A and less O individuals with allele Hp*2 and genotype Hp 2-2, and more Hp*1 among O individuals.

Genetic variants in the enhancer region of the thymidylate synthase gene in the Chilean population

“…The frequency of the allele TSER * 3 in the Chilean population appears to be incompatible with its ethnic origin. By contrast, all previous population studies of genes in the Chilean population have produced results consistent with the hypothesis of ethnic mixture [14, 22, 23]. Which factors may have been important in producing the current observed frequencies?…”

“…Considering that genetic markers in the Chilean population have generally shown allele frequencies between those observed in European Caucasians and Amerindians (of Mongoloid origin) [14, 22, 23] and that the percentage of Amerindian admixture in CLC is lower than in SJH, our results for the TSER locus are surprising; we expected to find a greater frequency of allele TSER * 3 in HSJ than in CLC. In order to estimate expected frequencies, we must suppose that: (i) the Spanish population which mixed with the indigenous group had a TSER * 3 allele frequency similar to that found in the current Spanish population (57%) [24]; (ii) the indigenous Chilean population had a TSER * 3 allele frequency similar to that found in current Mongoloid groups (81%) [7]; and (iii) the estimates of admixture are close to the real values.…”