A total number of 219 children from three different regions (low land, hill and mountain country) was examined for the presence of antibodies to a panel of antigens used in studies of atherosclerosis. The average percentage of antibodies found in an unselected group of children aged from 6 to 15 years was 31. This finding would assume the abnormal metabolic defect already in the first and second age decades, accompanied by a subsequent formation of antibodies. The authors discuss its causes and assume that the defect is reversible and can be influenced by a later way of life. The complement consumption test was used as a method of examination.