Causes of Hemochromatosis
There are different causes of hemochromatosis, based on the type of the disorder the person has. Hereditary hemochromatosis is linked to two known mutations in a gene called HFE. Acquired hemochromatosis causes, on the other hand, are other existing medical conditions, such as sideroblastic anemia, thalassemia, porphyria cutanea tarda, and liver disease. The causes of juvenile and neonatal hemochromatosis are unknown.
There are two types of hemochromatosis:
- Hereditary hemochromatosis
- Acquired hemochromatosis.
Genetic, or hereditary, hemochromatosis is mainly associated with a defect in a gene called the HFE gene, which helps regulate the amount of iron absorbed from food. Acquired hemochromatosis, on the other hand, occurs as a result of certain medical conditions.
Causes of Hereditary Hemochromatosis: HFE Mutation
Hereditary hemochromatosis can occur when a person inherits two mutated copies of the HFE gene — one from each parent. A mutation is a change in a gene that causes it to not work properly. Men and women have the same chance of inheriting two copies of this gene.
A person with only one copy of the mutated HFE gene is usually healthy and is said to be a "carrier" of the genetic condition. Although a carrier usually does not have hemochromatosis, if both a mother and father are carriers, a child may inherit two copies of the mutated HFE gene, one from each parent.
The HFE genetic defect of hemochromatosis is present at birth, but symptoms of hemochromatosis rarely appear before adulthood. Also, not everyone who is born with two copies of the mutated HFE gene develops the disease. Hemochromatosis research scientists do not know what percentage of people who have two copies of the mutated HFE gene develop the disease. Some studies have shown that as few as 1 in 100 people will develop symptoms. Other studies have shown that as many as 50 in 100 people may develop hemochromatosis symptoms.
(Click Hemochromatosis Gene to learn more about this cause of hemochromatosis, including certain mutations in the HFE gene that are more likely to cause the condition.)