How common is hemochromatosis?
Hemochromatosis is the most common genetic disorder for individuals of European descent. About 1 in 9 individuals of European ancestry carry at least one defective copy of HFE. Approximately 1 in 200 individuals of European ancestry carry two defective copies of HFE and are at increased risk of developing hemochromatosis. While both men and women can inherit the defective gene, men are more likely to be diagnosed. On average, men develop symptoms between the ages of 30-50, compared to women who are diagnosed after 50, often 10-15 years after menopause.

Symptoms of hemochromatosis
Hemochromatosis is hard to diagnose, because it involves symptoms that are also seen in many other health conditions. Excess iron accumulation occurs in affected individuals from a young age, but the symptoms of hemochromatosis do not appear until later in life. Men generally begin to show symptoms in their early 40s, while women have a later age of onset, due to the loss of blood (and excess iron) each month during menstruation.

Early symptoms include:

• Fatigue and weakness
• Characteristic “Iron Fist” (knuckle pain)
• Memory problems
• Depression
• Shortness of breath
• Heart flutters
• High blood sugar
• Low thyroid function

If hemochromatosis is untreated, the excess iron continues to accumulate in the body, causing serious and often fatal health complications:

• Diabetes
• Infertility
• Irregular heart rate and heart failure
• Enlarged liver, resulting in cirrhosis, liver disease and
  liver cancer
• Osteoarthritis and osteoporosis

Treating hemochromatosis
If the disease is detected early before organ damage has occurred, hemochromatosis is easily treated. Treatment can include blood removal every 2 – 4 months as an effective way to remove excess iron. If a diagnosis is made at later stages after organ damage has occurred, the damages are irreversible.

DNA testing for hemochromatosis
This DNA test identifies three specific changes in the HFE gene that are associated with an increased risk of hemochromatosis. C282Y is the most common mutation causing hemochromatosis and is associated with the most severe symptoms. H63D and S65C are two other mutations that occur in the HFE gene and can increase the risk of hemochromatosis, however often other precipitating factors (e.g. hepatitis or alcohol abuse) are also required before iron overload occurs.

To be at an increased risk of hemochromatosis, two defective copies of the HFE gene need to be inherited. Carriers, who have one normal and one defective HFE gene, are generally unaffected.

Likelihood of symptoms
Although individuals who inherit two defective HFE genes are at increased risk of developing hemochromatosis, many will not show any disease symptoms. At least 50% of C282Y homozygotes (who carry two copies of the C282Y mutation) show biochemical changes (e.g. raised serum transferrin saturation). However, only 28% of male and 1% of female C282Y homozygotes suffer from definite disease manifestation and show the symptoms described above. Additional modifying genes or other factors (e.g. alcohol abuse) are thought to contribute to the risk of hemochromatosis in genetically-susceptible individuals.