Haemochromatosis
Haemochromatosis is an inherited disorder that causes the body to absorb too much iron. Over the life of a patient, this leads to iron overload and finally, to major organ damage (e.g. liver, pancreas, heart). Inherited haemochromatosis is most commonly found in the Caucasian (Anglo-Celtic) population. Unfortunately the symptoms of haemochromatosis are similar to other common disorders, therefore the diagnosis is often missed or diagnosed late only when the serious symptoms have presented.
Approximately 1 in 9 Caucasians carry the gene for inherited haemochromatosis, while 1 in every 300 has the disease, in some cases, without knowing. The mutation in a patient’s DNA that causes inherited haemochromatosis is found on a gene called HFE. Everyone carries two copies of each gene, one inherited from their mother, the other from their father.
Inherited haemochromatosis is known as a recessive disorder, that is, you need two copies of the DNA mutation in the HFE gene to have the disease. In this case, the patient is known as a homozygote. If you have only one copy, you are known as a carrier, or heterozygote.
There can often be no previous family history of problems with body iron levels. This can be the case if both parents are carriers (have only one copy of the mutation in the HFE gene) but do not have the disorder. Their children will have a 1 in 4 chance of inheriting two copies of the mutation, hence develop haemochromatosis.
How is inherited haemochromatosis diagnosed?
Diagnosis is usually made by a simple blood test that looks for iron levels in the blood. If this test suggests iron overload your doctor may request a gene test to look for the mutation in the HFE gene. He may also request the HFE gene test if another family member has been diagnosed with inherited haemochromatosis.
The Healthscope Molecular HFE gene test looks for the two most common disease-causing mutations in the HFE gene known as C282Y and H63D. These mutations are found in more than 90% of people who have inherited haemochromatosis. If both of these mutations are absent then there still may still be a small chance that you have inherited haemochromatosis, since all disease causing mutations have not yet been found.
Some people can inherit one copy of the C282Y mutation, and one copy of the H63D mutation. These people are known as compound heterozygotes. These people may be at risk of iron overload, but usually do not develop clinical symptoms.
Treatment for inherited haemochromatosis
Once diagnosed, the treatment for haemochromatosis is called phlebotomy, a procedure that involves removing blood from the body. This treatment would occur on a regular basis, just like being a blood donor. With time the levels of iron in the blood should reduce. The earlier haemochromatosis is diagnosed and treated, the more likely it is to prevent major organ damage.
Who Should Be Tested?
- Patients with unexplained elevated iron levels in the blood.
- Patients with cirrhosis of the liver.
- Family members of individuals diagnosed with haemochromatosis.
- Family members of individuals who are homozygous for the C282Y mutation.
- Family members of individuals who are compound heterozygotes for the HFE gene.
Other sources of information
- www.gesa.org.au
- http://www.betterhealth.vic.gov.au
- http://www.haemochromatosis.org.au
- www.genetics.com.au/factsheet/36.htm
| Medicare Rebate available: | Yes |
| Specimen Type: | Whole Blood |
| Test Frequency: | Three times / week |