Haemochromatosis
General Information
Haemochromatosis is a chronic (long-term) disorder of iron metabolism involving the excessive absorption and inappropriate storage of iron. It occurs most commonly in New Zealanders of Celtic, Anglo and Northern European descent.
Iron is a mineral essential for life. It binds with haemoglobin, a molecule in the blood, to transport oxygen from the lungs to all the tissues of the body. During digestion the body absorbs iron through the intestines. In people without haemochromatosis the body only absorbs as much iron as it needs, with the rest being excreted by the body. However, in people with haemochromatosis, absorption is uncontrolled and the body absorbs excessive amounts of iron. The excess iron is unable to be utilised by the body and is deposited in body organs such as the liver, heart, pancreas and kidneys. This excess iron is toxic to the organs and over time can lead to damage and loss of function.
Haemochromatosis is an inherited (genetic) condition and is considered to be the most common genetic disease in the world. In New Zealand approximately 1 person in every 200 has the condition, while approximately 1 in 7 people of European descent are carriers. Haemochromatosis is diagnosed more commonly in males, as women tend to lose iron during regular menstruation.
The condition may also be known as Iron Overload Syndrome, Inherited Iron Overload Disease and Bronze Diabetes. Other causes of iron overload include multiple blood transfusions, chronic hepatitis C infection, alcoholic liver disease and various haematological (blood) disorders.
Signs and Symptoms
Signs and symptoms will vary depending on which organs are affected. Early signs and symptoms are commonly non-specific and can mimic other conditions.
Early symptoms may include:
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Fatigue
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Joint pain
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Stomach pains
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Weight loss
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Sexual dysfunction
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Poor general health
There may also be abnormalities in liver function tests in the absence of any symptoms.
As the condition progresses, more serious problems may occur including:
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Severe fatigue
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Thyroid damage
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Liver disease, including enlarged liver, hepatitis, cirrhosis of the liver, liver cancer and liver failure
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Abnormal pigmentation of the skin, making it look grey or bronze
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Heart abnormalities including heart rhythm problems and angina
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Damage to the adrenal glands
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Damage to the spleen
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Inefficiency of the immune system leading to infections and illness
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Neurological problems
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Infertility
Causes
Haemochromatosis is caused by a mutated gene. Discovered in 1996 the gene is known as the HFE gene. This is a recessive gene, meaning that a child with haemochromatosis must have received the gene for haemochromatosis from both parents and will have two copies of the gene. A carrier will have one copy of the gene but not have the disease.
For example
If both parents have haemochromatosis then they both have two copies of the gene. All their children will have haemochromatosis.
If both parents are carriers then they both have one copy of the gene. There is a one in four chance of a child having haemochromatosis, two chances in four that they will be carriers and one chance in four that they will neither have haemachromatosis nor be a carrier.
If one parent has haemochromatosis (ie: has two copies of the gene) and the other parent is a carrier (ie, has one copy of the gene), the children will have haemochromatosis or be carriers for the condition.
If one parent has haemochromatosis (ie, has two copies of the gene) and the other parent does not have a copy of the gene, then all the children will be carriers, but will not have the condition.
Diagnosis
Early diagnosis is vital in order to prevent organ damage. However, as the condition can take years to become apparent, and symptoms mimic other conditions, diagnosis can be difficult.
If haemochromatosis is suspected, the diagnosis can usually be confirmed by blood tests. The blood tests will check iron saturation (how much iron is in the blood) and serum ferritin levels (how much iron is stored).
The normal iron saturation level is between 20 and 40%. The normal serum ferritin levels are between 20 – 250 µg/L (micrograms per litre) for an adult male and between 20 – 160 µg/L for an adult female. Haemochromatosis will be suspected if the iron saturation is above 55% and the serum ferritin is above 400 µg/L.
The doctor will also take a full medical history, including any family history of haemochromatosis and will discuss current symptoms. This, combined with the characteristic blood test results, will assist with the accurate diagnosis of the condition.
In some cases, a liver biopsy may be performed in order to help confirm the diagnosis and to exclude liver damage. Additionally, x-rays and specialised scans may be necessary to assess whether damage has occurred in other organs.
Once a diagnosis of haemochromatosis has been made, it is usually recommended that close blood relatives (siblings, children, parents) are screened for the condition. Whilst haemochromatosis cannot be prevented, early diagnosis and treatment can prevent the development of symptoms and long term consequences of the condition.
Treatment
Once diagnosed, treatment for haemochromatosis is lifelong and involves the removal of excess iron. This is done by removing blood in a process similar to blood donation called venesection. Blood is removed at weekly sessions until the ferritin level is below approximately 100 µg/L. After this is achieved, blood is taken as often as necessary to keep ferritin at this level (approximately three to four times a year).
If organ damage occurred prior to the diagnosis of haemochromatosis, treatments aimed at repairing the damaged organ will be necessary. If permanent and severe damage has occurred, an organ transplant may be required.
General lifestyle guidelines for people with haemochromatosis include:
Further Support
For further information and support please contact your doctor, practice nurse, or the New Zealand Haemochromatosis Support and Awareness Group. .
New Zealand Haemochromatosis Support and Awareness Group (IRONZ)
PO Box 23-072
Papatoetoe
Auckland
E-mail: info@ironz.org.nz
Website: www.ironz.org.nz
References
Bosworth, M. Q. (2005) Hemochromatosis. The Gale Encyclopedia of Genetic Disorders, Second Edition. Brigham Narins, Editor. Farmington Hills, MI Thomson Gale.
Centers for Disease Control and Prevention (2006) Overview on iron overload and hemochromatosis Atlanta, GA: Centers for Disease Control and Prevention. http://www.cdc.gov/nccdphp/dnpa/hemochromatosis/
overview.htm
Gill, M. (ed.) (2000) Haemochromatosis. In Gill, M. A handbook for the interpretation of laboratory tests (3rd ed.) (pp185-186) Auckland: Diagnostic Medlab Ltd.
Gill, M. (ed.) (2000) Iron-binding capacity (IBC) and saturation. In Gill, M. A handbook for the interpretation of laboratory tests (3rd ed.) (p239) Auckland: Diagnostic Medlab Ltd.
New Zealand Haemochromatosis Support and Awareness Group (Ironz) (1999) Haemochromatosis (iron overload disorder) (pamphlet) Auckland: IRONZ New Zealand Haemochromatosis Support and Awareness Group
Last Reviewed - 21/02/07
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