What is hemochromatosis?
Hemochromatosis is an iron metabolism disorder that may be inherited or acquired. People with hemochromatosis accumulate more iron than their body needs. As the body does not have a way to excrete excess iron, there is a progressive buildup of iron in tissues and organs.
Eventually, the iron overload can lead to dysfunction and failure of several organs, notably the heart, liver, and endocrine portion of the pancreas. Complications include arthritis, diabetes, liver cirrhosis, heart arrhythmias and heart failure, and an increase in skin pigmentation called "bronzing."
There are two types of hemochromatosis: primary hemochromatosis, an inherited form that is passed from one generation to the next, and secondary hemochromatosis, which is caused by some other disease or underlying condition.
Primary or Hereditary Hemochromatosis (HH)
Hereditary hemochromatosis (HH), also called primary hemochromatosis, is one of the most common genetic disorders in the U.S., affecting about one million people, most of them Caucasians. The disease is usually caused by a mutation in the HFE gene. Everyone has two copies of the HFE gene – one inherited from their mother and one inherited from their father.
The mutations lead to changes in the building blocks of proteins, termed amino acids, and they are commonly referred to by the changes they induce in these amino acids. For example, the most common mutation involves changing from an amino acid called cysteine (C) to one called tyrosine (Y) in the 282nd amino acid of the protein made by the HFE gene; this mutation is called C282Y.
There are several mutations in the HFE gene that can cause hemochromatosis. The probability of developing iron overload depends on the combination of genes inherited.
Secondary or Acquired Hemochromatosis
Secondary hemochromatosis is an acquired iron overload that can be due to a variety of other diseases and conditions. Examples include: