Incidence of familial hypercholesterolaemia in premature deaths due to coronary heart disease

Cholesterol estimations were performed on blood collected postmortem from a group of subjects coming to autopsy and showing that they had had a high risk for hypercholesterolaemia, and from an unselected group of subjects dying in hospital. Subjects from the first group had apparently been healthy, aged less than 45 years, had had no known risk factors for hyperlipidaemia, and showed extensive coronary artery atheroma (stenosis greater than 50% by diameter). Eleven cases from 485 consecutive autopsies fulfilled these criteria; three showed considerable hypercholesterolaemia (11.2, 11.8, and 21.6 mmol/L). Family studies confirmed the diagnosis of familial hypercholesterolaemia in one case; the other two remain unproven. Cholesterol measurement by cholesterol oxidase and quinoneimine dye production is subject to interference by haemolysis; provided that serum haemoglobin is less than 200 mg/dl, the cholesterol underestimate is less than 5%. The decline in serum cholesterol in the group of unselected subjects was 1.7 (0.3-4.9) mmol/L, 50.4 (28-84) h postmortem. Results are means and ranges for seven subjects. Measurement of cholesterol in serum obtained postmortem (provided that the sample is not grossly haemolysed) is a valid approximation of antemortem levels: this measurement should be made when autopsy reveals evidence of premature coronary heart disease. If hypercholesterolaemia is discovered, the diagnosis of familial hypercholesterolaemia, a common genetic disorder inherited in an autosomal dominant fashion, should be considered and appropriate family studies instituted.