The tests below are used to detect and diagnose hemochromatosis and evaluate body organs for the severity of iron overload. They may also be used to monitor the effectiveness of treatment. Genetic testing may be used to confirm a diagnosis, but since many people who have genetic mutations associated with the disease never develop symptoms, blood tests are considered the most reliable form of diagnosis.
Laboratory testing typically includes:
- Serum iron — used to check iron levels in the blood
- Total iron-binding capacity (TIBC) — measures the total amount of iron that can be bound by proteins in the blood; transferrin is the primary iron-binding protein and the TIBC test is a good indirect measurement of transferrin availability.
- Transferrin saturation — a calculation using the iron and TIBC test results, representing the percentage of the transferrin that is saturated with iron; it is elevated with hereditary hemochromatosis (HH) but is not specific for it.
- Serum ferritin — used to evaluate the body's iron stores; it may be elevated with HH but is not specific for it. In those who have HH genes, normal levels mean low risk for developing organ damage.
- Liver panel — a group of tests used to evaluate liver function
- Genetic testing — can be used to help confirm a diagnosis of HH. Most cases of HH, about 80-90%, are caused by two copies of a C282Y mutation in the HFE gene. The presence of the C282Y mutation does not necessarily mean that a person will develop the disorder but does indicate an increased risk, and men are more likely to be affected than women. The largest population study found about a 25% risk among men and 1% risk among women.
Sometimes an H63D or S65C mutation of the HFE gene or paired combinations of the three may cause HH. Rarely, the condition may be due to another genetic abnormality.
- Liver biopsy — in rare cases, the diagnosis is confirmed by examination of a liver biopsy specimen for iron accumulation and liver damage.
An MRI (magnetic resonance imaging) test may be used to help evaluate the amount of iron in the liver.