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
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 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.
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.
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