Hemochromatosis
Diagnosis
Hereditary hemochromatosis can be difficult to diagnose. Early symptoms such as stiff joints and fatigue may be due to conditions other than hemochromatosis.
Many people with the disease don't have any signs or symptoms other than elevated levels of iron in their blood. Hemochromatosis may be identified because of abnormal blood tests done for other reasons or from screening of family members of people diagnosed with the disease.
Blood tests
The two key tests to detect iron overload are:
- Serum transferrin saturation. This test measures the amount of iron bound to a protein (transferrin) that carries iron in your blood. Transferrin saturation values greater than 45% are considered too high.
- Serum ferritin. This test measures the amount of iron stored in your liver. If the results of your serum transferrin saturation test are higher than normal, your doctor will check your serum ferritin.
Because a number of other conditions can also cause elevated ferritin, both blood tests are typically abnormal among people with this disorder and are best performed after you have been fasting. Elevations in one or all of these blood tests for iron can be found in other disorders. You may need to have the tests repeated for the most accurate results.
Additional testing
Your doctor may suggest other tests to confirm the diagnosis and to look for other problems:
- Liver function tests. These tests can help identify liver damage.
- MRI. An MRI is a fast and noninvasive way to measure the degree of iron overload in your liver.
- Testing for gene mutations. Testing your DNA for mutations in the HFE gene is recommended if you have high levels of iron in your blood. If you're considering genetic testing for hemochromatosis, discuss the pros and cons with your doctor or a genetic counselor.
- Removing a sample of liver tissue for testing (liver biopsy). If liver damage is suspected, your doctor may have a sample of tissue from your liver removed, using a thin needle. The sample is sent to a laboratory to be checked for the presence of iron as well as for evidence of liver damage, especially scarring or cirrhosis. Risks of biopsy include bruising, bleeding and infection.
Screening healthy people for hemochromatosis
Genetic testing is recommended for all first-degree relatives — parents, siblings and children — of anyone diagnosed with hemochromatosis. If a mutation is found in only one parent, then children do not need to be tested.