What is haemochromatosis?
Dr Sara Trompeter, Consultant Haematologist and Paediatric Haematologist at University College London Hospitals and NHS Blood and Transplant, answers common questions about haemochromatosis.
Haemochromatosis is an inherited condition which results in too much iron being stored in the body.
Your body doesn’t have a way of getting rid of the iron overload, so if you have too much it gets deposited in the organs - particularly the liver, but at higher levels it can enter the heart, pancreas and other organs.
It takes a long time for the iron to build up, so for the common type of hereditary haemochromatosis, symptoms are usually first seen between the ages of 30 and 60. It can take longer for symptoms to be seen in women, as they have periods and are therefore losing iron each month naturally.
If your ferritin levels are raised, and in the absence of any other cause, you should be referred for genetic testing to see if you do have haemochromatosis
Often the diagnosis is suspected due to abnormal blood tests often before any symptoms appear. The first symptoms people may notice are tiredness and darkening of the skin, or not feeling quite right. Later symptoms may be due to the effects of organ damage. If the high iron levels have damaged your liver, you may get fibrosis (hardening and scarring of the liver, which over time stops it from working as well) which may develop into cirrhosis, which is severe scarring that damages the function of the liver. There is also a small possibility of liver cancer. Higher-risk patients are often screened to check for these complications.
How can haemochromatosis affect my heart?
A build-up of iron in the heart can cause heart failure and abnormal heart rhythms. This is a very significant problem which will needs careful management. Iron will come out of the heart with treatment, but only slowly, sometimes over many months, and so the heart problems may continue. Sometimes patients need a pacemaker to regulate the heart rhythm. It is very important that this is an MRI-compatible pacemaker as MRI scans will be needed for further monitoring.
If the pancreas is damaged, this can lead to diabetes.
How is haemochromatosis diagnosed?
Sometimes haemochromatosis is spotted as a result of a ferritin test. This is a blood test that measures iron stored in the body. If your ferritin levels are raised, and in the absence of any other cause, you should be referred for genetic testing to see if you do have haemochromatosis. The ferritin test is also a guide to how severe the condition is. Those patients who have higher ferritin (above 1,000 micrograms per litre) may require closer monitoring after the initial phase of treatment, as they are more likely to develop long term problems.
If my ferritin is raised, do I definitely have genetic haemochromatosis?
No, there are lots of causes of a raised ferritin, but genetic haemochromatosis is one of them and your doctor should refer you for further genetic testing if your ferritin is persistently raised (or refer to a doctor that can) to determine if that is the cause.
How is haemochromatosis inherited?
Haemochromatosis is an autosomal recessive disorder. That means both parents need to be carriers (have one faulty gene), or be affected by the disorder (in which case they will have two faulty genes), and pass the affected gene to their child for the person to have the disorder. When two carrier parents decide to have a baby, there is a one in four chance of the child having the disorder.
As it is a recessive disorder, often parents don’t realise they are carrying the faulty gene. So in many cases there is not a family history.
I have genetic haemochromatosis, how do I know if my organs are affected?
When two carrier parents decide to have a baby, there is a one in four chance of the child having the disorder
Your doctor may well do further blood tests, for example to test the thyroid and sex hormones such as testosterone and oestrogen, and to check if you may have diabetes.
Looking for iron in the heart and liver is more complex and is done using MRI scanners with specialised technology in order to analyse the data, or sometimes a liver biopsy.
How severe is my genetic haemochromatosis?
Generally we look at the ferritin, and those patients who have higher ferritin (above 1,000 micrograms per litre) may require closer monitoring after the initial phase of treatment as they are more likely to develop long term problems, particularly of the liver.
How can the iron be removed?
Most commonly we remove the iron with repeated venesection, which means removing blood. This is very like what happens when you donate blood. Your body will make up the blood that is lost using some of your iron stores. So having repeated venesections will result in a gradual reduction of your iron stores.
Your doctor will discuss with you how much blood ought to be removed at each session and how often these sessions should be. These decisions will be based on several factors. For example, if your ferritin is very high, you may need more blood removed. If you are large, you will have a higher blood volume and will be able to have more removed than someone who is small. Those with a higher resting haemoglobin (blood count) can often come more frequently, even as much as twice a week. Generally at the beginning of treatment people tend to come for a venesection once a week, but if it is mild they may decide to come alternate weeks.
What happens when most of the iron is removed? How do we stop it accumulating again?
Once the ferritin is low then you move onto the maintenance programme. Here you will often need venesection every 3-4 months, or sometimes it may be longer gaps.
Can’t I donate blood through the National Blood Service, so that my blood is put to good use?
You can donate blood through the blood service if you are eligible to do so once you reach the maintenance phase. The blood service will need a letter from your doctor saying that you are now in maintenance phase. The blood service will not be monitoring your haemochromatosis or checking your ferritin, so you will still need to attend your appointments to do that.
I’ve heard that some people have a hard time having blood removed. Are there any alternatives?
Some people have more prominent veins than others, and some patients may find that there is difficulty in getting the veins to work sufficiently well for the blood to come out. You can help this by drinking well before the venesection and being warm and relaxed. If your medical team has had trouble before, it’s absolutely fine to tell the person who is about to do the venesection that this has been the case, as they may want to ask one of the more experienced staff to help out.
You can donate blood through the blood service if you are eligible to do so once you reach the maintenance phase
Some patients have fluids run in through a different vein at the same time during the venesection if they are sensitive to changes in blood volume.
Sometimes due to heart problems or co-existing blood problems, venesection may be unsuitable. In this case medication, called chelation, can be used to make the iron come out in the urine or stool. These are not used often, as they are expensive, have side effects and need close monitoring.
Which genes cause haemochromatosis?
The most common genes involved are called the HFE gene, which is involved in regulating iron levels in the body. The variants (faults) of this gene we usually test for are the C282Y and the H63D variants. The C282Y is the more severe of the two. These are most common in people of Celtic descent. There are other variants which can be involved, but generally we do not look for those unless there is evidence of excess iron and the common variants are normal.
My brother has genetic haemochromatosis. My ferritin is normal. Does that mean I do not have genetic haemochromatosis?
No, it doesn’t. Iron is accumulated slowly. If the commonest genes are affected it is unlikely that your ferritin will reach high levels before adulthood. Even then it may take years, especially for women who have periods and are therefore losing iron each month naturally. To be sure whether you have it or not you would need a genetic test.