LETTER TO THE EDITOR Haptoglobin genotypic distribution (including Hp allele) and associated serum haptoglobin concentrations in Koreans

Background: Haptoglobin polymorphism is associated with the prevalence of infections, autoimmune diseases, cardiovascular diseases, and other disorders. Congenital haptoglobin deficiency is associated with anaphylactic transfusion reactions in anhaptoglobinaemic patients with antihaptoglobin antibody. Aims: To investigate haptoglobin genotypic distribution (including the Hp allele) and associated serum haptoglobin concentrations in Koreans. Methods: Five hundred and nine healthy Korean adults were randomly selected. Two methods were used: haptoglobin genotyping based on a polymerase chain reaction (PCR) system that exploited the structural difference of the Hp and Hp alleles, and another PCR method that detected haptoglobin gene deletion by amplification of the junctional region of the Hp allele. Serum haptoglobin concentrations were measured by nephelometry. Results: The haptoglobin genotypes of 509 subjects were as follows: HpHp, 7.1%; HpHp, 37.7%; HpHp, 49.3%; HpHp, 2.2%; HpHp, 3.5%; HpHp, 0.2%. The gene frequency of Hp in Koreans was calculated to be 0.031. Significant differences were seen among the concentrations of each haptoglobin genotype (Kruskal-Wallis test). HpHp, but not HpHp, was associated with hypohaptoglobinaemia. Conclusions: PCR methods for differentiating between haptoglobin genotypes, including the Hp allele, may be useful in a broad spectrum of basic studies and clinical examinations.