[Family study of primary hypercholesterolemia in school children--the Tsukuba Study].

: Ninety-one children were determined to have hypercholesterolemia from a screening of 1,469 school children in the community near University of Tsukuba, and family studies of these children were performed. More than 50% of the parents participated in the study. The mean cholesterol levels of parents of hypercholesterolemic children were significantly higher than that of controls. Hypercholesterolemia in parents of hypercholesterolemic children was more frequent than that in controls. Nine families with autosomal dominant hyperlipidemia including familial hypercholesterolemia and familial combined hyperlipidemia were detected by further family studies. These results indicate that genetic factors are important as causes of hypercholesterolemia of school children and that family studies of hypercholesterolemic children is an efficient method for screening for persons with increased risk for cardiovascular diseases.