Health Centres - Haemochromatosis
What is haemochromatosis?
Haemochromatosis is a disease caused by excess iron in the body.
Iron is needed in the diet to maintain good health, particularly for making red blood cells that carry oxygen around the body. These red blood cells contain large amounts of iron.
Lack of iron can cause anaemia but excessive iron is toxic. The body has few ways of disposing of unwanted iron, so it builds up in tissues causing damage and disease.
What causes haemochromatosis?
Iron overload may be caused by increased absorption of iron from the intestine even when the body does not require it. This is called primary iron overload. This is usually caused by an inherited abnormality known as hereditary haemochromatosis.
Are there any other causes?
This article provides details on hereditary haemochromatosis but excess body iron may also be caused by large numbers of abnormal red blood cells being destroyed and releasing their iron. This is known as secondary iron overload and it may also be inherited.
Causes of this condition include blood disorders such as thalassaemia major and haemolytic anaemia.
Why or how do I get haemochromatosis?
Primary haemochromatosis is an inherited disease.
It is thought to be mainly caused by a mutation of a gene called HFE, which probably allows excess iron to be absorbed from the diet. This mutation is known as C282Y and to develop haemochromatosis you usually need two genes (one from each parent) to be C282Y. However, not everyone with the mutation may develop the disease and it may occur if only one C282Y gene is present.
Confusingly another mutation labelled H63D elsewhere on the HFE gene may occur alone or with C282Y and also influence iron levels.
Who is at risk?
Haemochromatosis is more common in Caucasian or white populations, with about 1 in 300 to 1 in 400 affected. About half that number are affected in black populations.
Men are more likely to have hereditary haemochromatosis and suffer from it at an earlier age, as women regularly lose iron in menstruation or use stores in pregnancy.
How does the disease develop?
The onset of hereditary haemochromatosis usually occurs between the ages of 30 and 60 as the build up of iron takes years. However, a rapid form of the disease does affect children. If left untreated excess iron builds up in the organs especially the liver, heart and pancreas. This may cause heart or liver failure, which can be fatal.
What are the symptoms of haemochromatosis?
As the iron overload increases, sufferers may experience the following diseases.
Liver disease: the liver is the main site of excessive iron build up. The disease causes scarring or liver fibrosis leading to cirrhosis. Symptoms include abdominal pain, jaundice, swelling of the ankles or abdomen and enlargement of the liver or spleen. In severe cases bleeding from the gut or coma can occur.
Heart disease: excess iron deposits may lead to one of two heart conditions. These are heart failure (indicated by tiredness, lack of energy, shortness of breath and ankle swelling) and abnormal heart rhythms. Patients may experience extra heart beats known as ectopics or disorders where the heart goes either too fast (tachycardia) or too slow (bradycardia).
Pancreatic disease: sugar diabetes (diabetes mellitus) may be an early sign of haemochromatosis and develops in up to half of all patients with advanced disease. Diabetes is due to excess iron in the pancreas gland damaging the insulin producing cells. This complication together with the dark skin pigmentation that can occur has led to haemochromatosis sometimes being called 'bronze diabetes'.
Other rare symptoms: endocrine gland problems particularly with pituitary, thyroid or sex hormones can occur, as can skin and neurological disease.
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