RESUMEN
An analysis of 422 Moscow hospital records of children suffering from acute leukemia during the period from 1959 and continuing through to 1979 showed that the proportion of those with morphologically "average" weight and body length values at birth, was significantly lower in the group with leukemia, than in the control group of healthy children. Genetic structure of leukemic and healthy children was found to be significantly different by phenotypic combinations of 2 loci (ABO and Rhesus). The distribution of children for their age at the beginning of the disease was studied. The results revealed that children with the low weight and body length values at birth, as well as those having ARh+ and BRh+ blood groups, develop leukemia earlier than those with "average" characteristics and blood groups other than ARh+ and BRh+. The anamnesis of children which developed leukemia demonstrated a higher infectious-inflammatory disease frequency, as compared with the control group. By comparison of some parental characteristics of two groups of children, it was found that parents of children which became ill, were on the average older at the moment of baby's birth than parents of healthy children. Babies of 2nd, 3rd and subsequent deliveries were registered more frequently in the group with leukemia than in that of healthy children. Evidence presented confirms the efficiency of the population-genetic approach to the problem of nonspecific resistance of human organism to diseases.