Abstract
The relationship between the serum ferritin concentration and total body iron stores was investigated in 41 patients with idiopathic haemochromatosis and 199 first or second degree relatives. Thirty-two relatives (16.1%) had increased iron stores and serum ferritin levels were increased in all but one of them. The false-positive rate in the relatives with normal iron stores was 1.8% compared with 10% for the serum iron concentration and 33% for the transferrin saturation. There was a significant correlation between the serum ferritin concentration and both the chelatable body iron and the hepatic iron concentration. We conclude that in the natural history of classical idiopathic haemochromatosis the serum ferritin concentration is usually raised when hepatic iron stores are increased and before there is architectural damage to the liver.