Two brothers, one with hepatic haemosiderosis and the other with hepatic haemochromatosis, died with clinical symptoms of acute abdominal pain and irreversible shock. In view of these deaths, 35 relatives were examined. The iron metabolism was studied by determination of the amount of stainable iron in the liver tissue, the fasting serum iron concentration, the iron saturation percentage of transferrin and the iron excretion in 24‐hours urine following intramuscular administration of 1000 mg desferrioxamine B.A defect in iron metabolism was found in three generations. The findings are most readily compatible with the view that a dominant autosomal gene is responsible for the occurrence of the metabolic defec