What is Haemochromatosis?
Haemochromatosis is a medical condition caused by an overload of iron in your body.
There are several forms of haemochromatosis. In genetic haemochromatosis, inheritance of a faulty or abnormal gene is responsible for an increase in the amount of iron entering the body.
Iron is a mineral that is essential to help your body grow and, as a nutrient, iron is important in your diet to help make haemoglobin, a vital protein in red blood cells. Haemoglobin gives red blood cells their colour and helps them carry oxygen around your body.
Iron enters the body when nutrients are taken in, or absorbed, by your small intestine following digestion. An overload of iron is caused by an increase in the absorption of iron from food.
About two thirds of the iron absorbed is incorporated into haemoglobin itself. Most of the rest is stored in your liver, with smaller amounts distributed to other organs and body tissue. Normally you should have around three to four grams (g) of iron in your body. Your body has no natural mechanism for getting rid of unwanted iron once it has been absorbed.
People with haemochromatosis absorb at least twice as much iron as normal. When more than five grams of iron has been absorbed, it will start to become deposited around the body. An excessive amount of iron can mean 20g or more.
The poisonous (toxic) effects of this extra iron mean that haemochromatosis is a potentially life threatening condition, but it can be treated effectively if diagnosed early enough.
How will haemochromatosis affect me?
Haemochromatosis can cause a range of problems in your body, primarily in the liver.
It is thought that the extra iron causes damage by increasing the production of harmful oxygen molecules in your body cells. Known as ‘free radicals’, these molecules are linked to other diseases and understood to play a role in the body’s aging process. They can be toxic when there are too many and this is made worse by the presence of iron. Free radicals will interact with other molecules to damage cells, tissues and organs.
In the liver this takes the form of scarring, known as fibrosis. Additionally, your liver may become enlarged (hepatomegaly). With ongoing liver damage, fibrosis may progress to cirrhosis. If this happens, you are at greater risk of liver cancer, known as hepatocellular carcinoma, or HCC.
Haemochromatosis is likely to lead to serious problems in other organs. Pancreatic damage leading to diabetes and dysfunction in the sexual glands are common, as is the development of arthritis. Heart disease may also develop. It will also increase your skin pigmentation (hyperpigmentation) so that your appearance develops a yellowish or bronzed effect.
Haemochromatosis is most commonly found in people of northern European descent. The highest frequencies of the disease are found in people from the British Isles and Ireland. Haemochromatosis occurs in both men and women although it is more likely to affect men becasue women lose iron each month through menstruation.
In the UK the genetic condition is found in about one in 200 people. However, only about one person in 5000 people is ever diagnosed with haemochromatosis. The fact that there are no specific symptoms associated with haemochromatosis supports the view of disease specialists and related health organisations that it is under-diagnosed by doctors and that the disease prevalence is higher.
How is haemochromatosis inherited?
Genetic haemochromatosis, as its name suggests, runs in families and is now recognised as one of the most common disorders of this type.
The disorder is caused by a gene. This is a segment of DNA containing the instructions for making up your body. Genes are packaged in a sequence on strands of DNA called chromosomes which are found in the nucleus of your body cells. All of us carry up to 30,000 individual genes.
All of your body cells should contain a gene inherited from your mother and one from your father. We generally carry the same genes as each other, but around 1% of genes will differ between people. These small differences are what contribute to each person’s unique physical traits.
The HFE gene contains instructions for producing a protein that helps with the digestion of food by managing the absorption of iron into your small intestine. When functioning normally this mechanism limits the amount of iron going into your body from your diet. It is thought that mutations on the HFE gene restrict its ability to control iron intake. This is linked to a deficit of hepcidin, a peptide or small protein responsible for regulating iron in your body.
There are actually two known common variants in the HFE gene that have been associated with iron overload. These are called C282Y and H63D. The numbers 282 and 63 indicate where the mutations are found on the HFE gene. The mutations occur on a specific chromosome (chromosome six).
The C282Y mutation is the more severe. It is found only among people of northern European origin and in the UK about one in eight people carry one copy of the HFE gene with the C282Y mutation but such ‘carriers’ are not at risk from iron overload.
The H63D variant is associated with a milder disease and usually only when inherited with a copy of the HFE gene having the C282Y mutation. It is spread more widely throughout the world and in the UK one in four people carry one copy of the HFE gene with the H63D variant. They are not at risk from iron overload.
In the UK about 90% of people with haemochromatosis have two copies of the C282Y mutation. About 5% have one copy of each mutation (C282Y/H63D) and the remainder have only one copy of the C282Y or H63D variants or no copies. These people may have other changes in the HFE gene or changes in other genes causing iron overload.
Not all people with haemochromatosis will therefore have typical gene mutations. To develop haemochromatosis that is linked to the HFE gene, both copies of the gene must be
affected. For this reason it is known as a ‘recessive’ disorder, as opposed to a ‘dominant’ disorder where only one gene is required.
In over 90% of people diagnosed with the disorder, both genes have been found to be abnormal. A person who has only one abnormal gene is known as a ‘carrier’. They are not usually affected but can pass on the gene to their own children. On average, half the eggs or half the sperm of a carrier will contain the abnormal gene.
A person who inherits the mutation from both parents will carry the abnormal gene in all of their eggs and sperm.
Scientists still have some way to go to be able to answer important questions about how genetic haemochromatosis occurs. It is still not known how many people with the defective HFE gene will go on to develop symptoms or why some people develop symptoms and others do not.
Although haemochromatosis is inherited, the build-up of iron in the body happens quite slowly and symptoms do not usually appear until a person is aged 30 or 40 years old. In women, this is commonly closer to 50 years. For many the lifetime build-up of iron is quite small and does not cause clinical problems. When symptoms do appear, they may include the following:
tiredness, fatigue or lack of energy
a feeling of weakness in your limbs
pain in the joints, especially in the knuckles and in the joints of your first two fingers
pain in your stomach or abdomen
loss of libido (sex drive) and possibly
impotence or early menopause
evidence of liver damage from scarring (fibrosis) and cirrhosis
cardiomyopathy (disease of the heart muscle)
type 2 diabetes
a yellowing or ‘bronzing’ of the skin.
Some people diagnosed with haemochromatosis report having mental confusion, mood swings and depression.
Doctors may investigate and rule out a range of other illnesses that share the same symptoms before haemochromatosis is suspected. Abnormal iron levels are often the only sign of haemochromatosis. Therefore, the most important tests for detecting iron levels in the blood are the transferrin saturation and serum ferritin tests.
Transferrin saturation (TS)
Transferrin is a protein that binds iron in the blood serum and carries it around your body. This test measures the level of iron in your blood against the capacity of the blood iron binding protein (transferrin) to bind it. This is known as the Total Iron Binding Capacity or TIBC.
Serum ferritin (SF)
Ferritin is the protein that stores iron in the tissues. Small amounts of ferritin are found in the blood serum and as the amount of iron in your body increases, so do the levels of ferritin in the serum.
Genetic testing is a more recent development in haemochromatosis and is used to determine whether you have the HFE gene mutation. Doctors may use the test to identify the cause of high iron levels detected in the TS and SF tests. Genetic testing is positive in over 90% of people with iron overload.
Liver function tests
If liver damage is suspected, liver function tests (LFTs) may also be used. These involve taking a sample of blood and looking at different properties of your blood to gain an idea of how much your liver is inflamed or damaged in its ability to work properly. In particular, doctors will be concerned to measure levels of the liver enzymes ALT and AST which are increased during liver inflammation (hepatitis).
The genetic test has reduced some of the need for liver biopsy to confirm haemochromatosis. However, if you have high serum ferritin (over 1000 mcg per litre) or signs of liver damage doctors may use a liver biopsy to confirm their diagnosis and to assess the severity of any liver fibrosis/cirrhosis.
During a liver biopsy a tiny piece of the liver is taken for study. To do this, a fine hollow needle is passed through the skin into the liver and a small sample of tissue is withdrawn.
As well as measuring liver damage, liver biopsy enables chemical analysis of the iron concentration in the tissue sample. This is useful when iron overload is suspected in people who do not have the ironloading genotype (the abnormal gene pairs likely to cause haemochromatosis).
In addition to blood tests and liver biopsy it may be necessary for medical staff to use ‘imaging’ equipment to help them detect the presence of iron build-up in your body. This is most likely to be a MRI scan, although ultrasound technology is sometimes used to guide a liver biopsy.
Magnetic Resonant Imagery (MRI) is a special tube scanner used to provide a detailed view of the liver. It creates powerful magnetic fields by releasing radio frequency energy to act on water molecules in your body. A type of radio signal is returned and picked up by the MRI equipment. This is relayed to a computer that can generate very detailed cross-sectioned images (or ‘slices’) of your liver area.
Diagnostic technology has been developed specifically for iron-overloading disease. ‘Ferriscan’ is a procedure that has been developed to analyze the MRI scans themselves in order to measure iron concentration.
If you have a family history of haemochromatosis, you should see a medical professional. Relatives may be at risk and need to be encouraged to be screened by genetic testing to find out whether they carry the HFE gene mutation (though children do not need to be tested until they reach adulthood and can decide for themselves). It is very important that brothers and sisters of someone diagnosed are screened because they are more likely to carry both abnormal genes.
Genetic counselling can help you to better understand the likely occurrence of haemochromatosis in your family or explain the implications of any diagnosis. You may wish to talk to a counsellor to find out more about an inherited disorder in your family or you can be referred for counselling by a GP or hospital consultant following diagnosis.
Treatment of haemochromatosis is simply aimed at removing iron from your body. As the body has no natural method for getting rid of the extra iron, this done by regular bleeding known as phlebotomy.
During phlebotomy a unit of blood, usually 450 millitres (ml), is removed. This amount will contain 220mg of iron. Bleeding in this way will activate the remaining stored iron to make new red blood cells.
You will be required to have phlebotomy up to once a week, depending on the degree of your iron overload. This may continue for up to two years. Over this period doctors will monitor your serum ferritin levels until they fall to a safe level (generally 20 mcg per litre). Removing blood does not stop the iron building up.
After your course of treatment you will need to have further phlebotomies two to four times a year for the rest of your life. Doctors will continue to monitor transferrin saturation and serum ferritin levels (ideally maintained at 50% and 50 mcg per litre respectively) to assess when phlebotomy may be required. This is known as ‘maintenance therapy’.
An enlarged liver may reduce in size but if cirrhosis has become advanced, improvement is unlikely. If you have cirrhosis, doctors may run blood tests and imaging tests at regular intervals (usually every six months). Having cirrhosis will put you at a much higher risk of developing hepatocellular carcinoma (HCC). If this occurs, a liver transplant may be required.
In diabetes, phlebotomy will not be able to repair damage to your pancreas. Other serious problems such as arthritis and sexual disorders arising from damage to the pituitary gland are unfortunately unlikely to improve.
Symptoms such as tiredness and abdominal pain should lessen with recovery. The colour of your skin should return to normal and if you have heart disease, such as cardiomyopathy, any improvement will be linked to the severity of any damage caused by haemochromatosis.
Looking after yourself
Medical staff may suggest that you regulate the amount of iron in your diet. Having haemochromatosis does not mean that you have to go out of your way to avoid iron. It is better that you try to balance your intake, as foods containing iron will also contain other nutrients that are essential for your general well-being.
How can I control the iron in my diet?
There are two different forms of dietary iron, known as haem and non-haem. Haem iron is found in animal tissues while non-haem iron exists in plant or vegetable material. The amount of iron you absorb from eating foods made from various plant sources ranges from around 1% up to 10%. Absorption from animal food sources is much higher, at between 10% and 20%.
You should avoid consumption of the following:
vitamins or multivitamin supplements that contain iron
Vitamin C in pill form as this increases absorption of non-haem iron. Vitamin C from fruit and vegetables does not need to be avoided
breakfast cereals that are ‘fortified’ with iron
shellfish such as oysters, mussels and clams as these contain a bacteria that may be fatal to people with iron overload.
Because of the increased absorption from animal foods you may wish to cut down on eating red meat. Offal (organs such as heart, liver, kidneys etc.) in particular is very iron-rich.
There are certain substances that should be included in your diet:
calcium, as found in dairy foods, limits the absorption of haem iron (it is therefore helpful to consume dairy foods when you are eating meat)
tannin, as found in tea, limits the absorption of iron.
It is a good idea to develop a habit of reading the package labelling on processed foods to find out their nutritional content. You may be surprised to learn that even certain breads may have too much iron for you.
While watching your diet is essential, it is important to note that it is very unlikely you will prevent the development of haemochromatosis or be able to avoid the need for phlebotomy by dietary means.
Alcohol and haemochromatosis
Studies show that the combination of alcohol and iron increases the way in which free radicals cause ‘oxidative stress’ in the body. This means that drinking alcohol is likely to speed up and worsen the impact of the disease. If you have cirrhosis you should avoid alcohol completely.
A common symptom of haemochromatosis is not having the energy to carry out physical tasks. This may improve with phlebotomy but you should talk to your medical advisor before undertaking any strenuous activity.
Please visit the support section of our website for information on Support groups in your area or visit our Useful Links section for other organisations who may be able to offer information and support.
The Haemochromatosis Society
PO Box 6356
Office: 03030 40110
Advice Line: 03030 401102
Promotes awareness among the health professions, patients and their families, the general public and policy makers.It encourages and supports research, publishes a quarterly newsletter and provides resource material for the medical professions.
Irish Haemochromatosis Association
The Carmichael Centre
North Brunswick Street
Provides support and information for people with haemochromatosis and related disorders in Ireland. It produces a newsletter, brochures and other media to provide information and raise awareness of haemochromatosis.
Download: Haemochromatosis HCT/04/16.pdf
Reviewed by: Professor Mark Worwood, Director of the Graduate School in Biomedical and Life Sciences, Department of Haematology, School of Medicine, Cardiff University: Peter Wells: Janet Fernau, Haemochromatosis Society