What is Haemochromatosis?
Haemochromatosis - or genetic haemochromatosis (GH) - is a disorder that causes the body to absorb an excessive amount of iron from the diet.
We can only use a limited amount of iron and any excess is deposited around the body. This accumulates mainly in the liver, but can also affect the heart, pancreas and pituitary gland, damaging these vital body organs and resulting in a deterioration of their functional capacity.
Symptoms
Although haemochromatosis and the potential for the condition to cause problems is present from birth, symptoms don't usually become apparent until middle age. Common symptoms that might be noticed then include:
- weakness, tiredness and lack of energy
- joint pain and stiffness - particularly in the hands and fingers
- a tanned or bronzed appearance of the skin
- impotence in men
- shrinking of testicles
- weight loss
- abdominal pain
Later, more serious symptoms may develop including:
- diabetes
- arthritis
- heart problems
- enlargement or damage to the liver
Causes and risk factors
Haemochromatosis runs in families and affects around one in 300 people in Europe.
Men are more likely to be affected than women. This isn't because of genetic susceptibility, but because women lose iron each month during menstruation. This means that even when an excess amount of iron is absorbed, less iron remains in the body to be deposited in the organs.
People with haemochromatosis who drink alcohol in unsafe amounts often develop symptoms before they reach 40 because alcohol increases the absorption of iron from the diet.
Genetic haemochromatosis is now recognised as being one of the most common genetic disorders. The process of inheritance is autosomal recessive. This means that to develop the disease a person must inherit an abnormal gene from both parents. There is a one in four chance of this happening when both parents are carriers of the abnormal gene.
If someone only inherits one abnormal gene, they won't develop the symptoms of the disease but they'll be a carrier and may pass the gene on to their children. More than 1 in 10 people in Europe are carriers of the gene mutation for haemochromatosis.
The condition can also be acquired, for example, as a result of frequent blood transfusions for haemolytic anaemia (blood contains iron).
It's important that haemochromatosis is diagnosed and treated as soon as possible, before severe and life-threatening damage is done.
Haemochromatosis weakens the heart, causing heart failure. It can also cause diabetes by damaging the pancreas, while damage to the liver increases the risk of liver cancer. When treatment is given early enough, such damage can be avoided.
Blood tests can reveal unusually high levels of iron stored in the body and scanning the organs of the body, such as the liver, helps to identify any organ damage. A liver biopsy may also be performed to establish whether iron has accumulated there.
Genetic testing may help to confirm the diagnosis – one particular gene mutation is responsible for more than 90 per cent of cases. But other genetic abnormalities may also cause the condition and may be more difficult to spot. When a person is diagnosed with genetic haemochromatosis, other close members of the family are usually offered screening for the disease.
Treatment and recovery
Haemochromatosis is treated by:
- Reducing the amount of iron absorbed by the body - patients are advised to avoid iron-rich foods and alcohol.
- Removing excess iron from the body by removing blood from the body (venesection therapy or phlebotomy). Initially this may involve removing a unit of blood a week (sometimes for many months) until iron levels in the blood are normal. Then most people can be kept stable by removing a unit of blood every 2-3 months.
If phlebotomy is started before liver damage occurs the outlook is good, and the affected person can expect to live an otherwise normal life.
Acquired haemochromatosis is normally treated by a drug that binds iron and allows it to be excreted from the body.
Associated problems such as heart failure and diabetes are treated as appropriate.
