Interaction between ABO and haptoglobin systems in a Chilean population ofmixed ancestry

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 wer e selected at random among those who began their primary school in 1973 in the Northern Metropolitan area of Santiago, Chile. This region has an Ameri ndian component of 40% and a Caucasian component (principally Spanish) of 6 0%. Our results are in contrast with previous studies which have reported t hat Hp*l varied among ABO groups in the following manner, O < A < B < AB, a nd where Hp*l was significantly lower in group O individuals. Tn the presen t study, the order was A < O approximate to B < AB. We found more A and les s O individuals with allele Hp*2 and genotype Hp 2-2, and more Hp*l among O individuals.