Causes of iron overload

Hereditary haemochromatosis is the syndrome of end-organ damage due to progressive iron accumulation caused by genetic disorders. It is the commonest genetic disorder of northern Europeans. In over 90% of cases the disease is associated with mutations in the HFE gene. Identification of the genetic basis of rare causes of hereditary haemochromatosis has greatly increased understanding of iron metabolism. Symptoms of haemochromatosis are frequently non-specific and include abdominal pain, arthralgia and general malaise. Iron accumulates predominantly in the liver, leading to liver dysfunction, and ultimately to cirrhosis and hepatocellular cancer. Iron accumulation in the pancreas and joints result in diabetes and degenerative arthritis. Diagnosis of the common form of haemochromatosis can be made in the majority of cases using biochemical tests of iron, transferrin and ferritin combined with genetic tests for mutations in HFE. Liver biopsy may reveal a characteristic pattern of iron deposition in periportal hepatocytes, with relative Kupffer cell sparing and liver fibrosis that may progress to cirrhosis. Treatment with phlebotomy removes iron in haemoglobin, drawing iron out of other tissues. This can effectively reduce the morbidity and mortality of the disease if diagnosed in the pre-cirrhotic state. Due to the poor specificity of symptoms, late diagnosis remains a problem and is associated with significant morbidity and mortality. Screening with biochemical and genetic tests, particularly in families, may prevent disease.