[Dependence of the concentration of maternal serum markers on the haptoglobin gene]

This paper is the first in a series devoted to the investigation of the possible effect of maternal genotype on the levels of fetal alpha-fetoprotein (AFP) and human chorionic gonadotrophin (HCG) entering maternal blood. We studied the possible association between the maternal haptoglobin system and levels of maternal AFP and HCG, which are markers of fetal pathology. Haptoglobin types were determined in groups of pregnant women with different levels of serum markers. Distribution of haptoglobin types differed from the theoretically expected in one out of five groups tested. In the group with low AFP level, a significant decrease in frequency of the Hp*2 allele was found. A statistically significant decrease of the mean haptoglobin concentration in the group with low levels of AFP and elevated levels of HCG was observed. A reduction in serum haptoglobin concentration was shown to be accompanied by a decrease of serum iron concentration. The possible mechanism underlying the influence of maternal genotype on the levels of AFP and HCG in maternal blood are discussed.