Iron Overload and Hemochromatosis: Causes and Risk Factors
In the United States, the most common form of hemochromatosis in adults
is called hereditary hemochromatosis or classic hemochromatosis. This form
of the disease is caused by a defect in the genes that control how iron is
absorbed by the body.
The amount of iron the human body absorbs is controlled by many genes.
Genes can sometimes change (or mutate) in ways that keep them from working
Hereditary hemochromatosis can occur when a person inherits two mutated
copies of a gene called the HFE gene — one from each parent. Men and
women have the same chance of inheriting two copies of this gene.
Not everyone who is born with two copies of the mutated HFE gene
develops the disease. 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
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 gene, one from
People who inherit the HFE gene mutation from both parents are at
the greatest risk for developing hemochromatosis. Although both men and
women can inherit the gene defect, men are more likely to be diagnosed with
the effects of hemochromatosis than women. Other factors that increase risk
are listed in the following table.
Reason for Increased Risk
||White people of northern European descent (for example,
families from England, Ireland, Scotland, Denmark, France, and
Scandinavia) have a higher chance of having the HFE gene
||People with a close relative (grandparent, mother, father,
sibling, niece, nephew) who has hemochromatosis have a higher
chance of having the HFE gene mutation.
Factors That May Affect Iron Buildup
For people at risk of developing hemochromatosis, the speed at which iron
builds up and the severity of the symptoms vary from person to person.
Many people do not have any early symptoms. Symptoms tend to occur in men
between the ages of 30 and 50 and in women over age 50.
The following factors may affect the buildup of iron in the body and may
speed up or slow down the development of hemochromatosis.
Potential Effect on Iron Buildup
|Use of dietary supplements
||Taking iron supplements or multivitamins with iron can speed
up the rate at which iron builds up in the body. Persons with
hemochromatosis should not take pills containing iron. Eating
foods that contain iron is fine.
Taking vitamin C supplements may cause the body to absorb
more iron. Persons with hemochromatosis should not take pills
with more than 500 milligrams of vitamin C per day. Eating foods
that contain vitamin C is fine.
||Losing iron by giving blood and losing iron through
menstruation and unrecognized bleeding may slow the start of
hemochromatosis. Therefore, men at risk for hemochromatosis
usually develop the disease and its symptoms at a younger age
than women who are at risk.
|People with the HFE gene
mutation may absorb extra iron from their diet each day. Over
many years, this extra iron may cause a buildup of iron in the
body that can lead to disease. Persons with hemochromatosis
should not take pills containing iron.
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