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.
