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Following a thorough medical history, physical examination, and blood tests to rule out other diseases or conditions that may be responsible for the patient's symptoms, a possible diagnosis of hemochromatosis should be suspected. Your doctor will order several laboratory tests to determine if you may have iron overload which may indicate the presence of hereditary hemochromatosis. These tests include:

• Serum iron test
• Fasting serum transferrin saturation percentage test
• Serum ferritin test
• Genotyping
• Liver biopsy
• Quantitative phlebotomy

Serum Iron Test

The serum iron test measures the amount of circulating iron in the bloodstream that is bound to transferrin and reflects total body iron levels. However, serum iron can be influenced by various factors including diet, menstrual cycle, time of day, and iron supplements and is, therefore, not a precise measure of iron status. The serum iron test is, therefore, used in combination with other tests in order to accurately measure the presence of iron overload.

Fasting Serum Transferrin Saturation Percentage

The fasting serum transferring saturation percentage test measures the amount of iron that is bound to the protein that carries iron in the bloodstream (transferrin) It is calculated by measuring the Total Iron Binding Capacity (TIBC), the maximum iron concentration that transferrin can bind, and serum iron.

In 2002, an expert panel convened by the U.S. Centers for Disease Control and Prevention recommended the following interpretation of results for the fasting serum transferring saturation percentage:

• Less than 16% saturation indicates iron deficiency
• 16-45% is considered normal with no indication of iron overload
• Greater than 45% indicates elevated values and may be indicative of iron overload

Although some doctors recommend a value of 60% or greater saturation level for men and 50% or greater saturation level for women, the lower value of 45% is more inclusive for detecting potential iron overload that may be missed at the higher value. If the transferrin saturation test is administered under non-fasting condition, the thresholds set for iron overload are higher. Fasting transferrin saturation percentage test is regarded by many clinicians as the most accurate diagnostic test for hereditary hemochromatosis.

Serum Ferritin Test

This test measures the amount of iron stored in the liver and is usually performed if a patient has an elevated (45% or greater) fasting serum transferrin saturation test. A serum ferritin level of 200 ng/mL or higher is considered as being elevated in pre-menopausal women and a level of 300 ng/mL or higher is considered elevated in men and in postmenopausal women. An elevated serum ferritin test alerts the doctor to the possibility of hemochromatosis and requires further follow-up including genetic testing for hereditary hemochromatosis. Serum ferritin levels of 1,000 ng/mL or higher strongly suggest damage to the liver and a liver biopsy is usually recommended to check for cirrhosis of the liver. The serum ferritin test is not specific for hereditary hemochromatosis and may be elevated in other conditions and, therefore, this test is used together with the serum transferrin saturation percentage to diagnose hereditary hemochromatosis.

Genotyping