The gene for hemochromatosis (called HFE) regulates how much iron is absorbed from the food we eat. Mutations in the gene cause hemochromatosis. When one copy of the mutated gene is inherited from one parent, the child is a carrier, but usually has no associated symptoms. When a child inherits two copies of a mutated gene (one from each parent), he or she is more likely to develop the condition.
The gene that causes genetic or hereditary hemochromatosis, called the HFE gene, was first identified on chromosome 6 in 1996. This gene helps regulate the amount of iron absorbed from food. When a mutation (change) occurs in the gene, there is a chance that a person can develop hemochromatosis.
Understanding the HFE Gene
The hemochromatosis gene provides instructions for producing a protein that is located mainly on the surface of intestinal cells, liver cells, and some cells in the immune system. During digestion, this protein helps certain cells regulate the absorption of iron into the small intestine by interacting with other proteins located on the cell surface.
The body uses this mechanism to help monitor its supply of iron. When the proteins involved in iron sensing and absorption are functioning properly, the body absorbs only about 10 percent of the iron ingested in the diet.
Hemochromatosis research suggests that the HFE protein also helps control levels of another important iron-regulatory protein: hepcidin. Adequate levels of hepcidin are necessary to ensure that the body does not absorb and store too much iron in its tissues and organs.