Celtic Curse: What Is Hemochromatosis and How Is It Acquired?

Thousands of years ago, a slight change in genomes likely offered some people an evolutionary advantage in their Northern European environment. They were given a better chance of absorbing iron from a diet that was sorely lacking in it.

That small change, however, turned deadly over time. The genetic disease from these variants, called hemochromatosis, can lead to toxic iron accumulation in a person's organs.

What is Hemochromatosis?

Hemochromatosis is a medical condition in which the body stores too much iron, eventually leading to multiple organ dysfunction. Also known as iron overload, it is the most common autosomal recessive disorder in white people, with a prevalence of 1 in 300 to 500 individuals.

Iron is a mineral found in certain foods. The body needs it to make red blood cells, produce certain hormones, and help hemoglobin carry oxygen throughout the body. Normally, the intestines absorb just the right amount of iron from the food a person eats.

Iron absorption is tightly regulated because the body is incapable of secreting excess iron. Too much iron is toxic and can cause arrhythmia and heart failure. It can also lead to cirrhosis, liver cancer, and liver failure. Additionally, iron overload also results in arthritis, diabetes, and erectile dysfunction. Hemochromatosis has also been called "bronze diabetes" because of the discoloration of the skin and related diseases of the pancreas.

Not every person with hemochromatosis develops symptoms. Some patients with high iron levels do not have any problems, while others suffer from serious symptoms. Symptoms typically do not appear until middle age and usually look like signs of other conditions. These signs may include fatigue, general weakness, heart flutters, iron fist, joint pain, stomach pain, and unexplained weight loss.

Although hemochromatosis cannot be prevented, people can get help controlling their iron levels. Healthcare providers can help avoid complications by identifying and treating this condition early.

What Causes Hemochromatosis?

There are two types of hemochromatosis, each with different causes. The most common reason is an inherited genetic change that leads to primary hemochromatosis. Also known as hereditary hemochromatosis, this condition arises from the DNA inherited from both parents. In secondary hemochromatosis, medical treatments or other medical conditions cause iron overload.

The inherited form of hemochromatosis is more common in white people with ancestors from Northern Europe. It is sometimes known as the Celtic Curse because it is particularly common in people with Irish or Scottish ancestry.

Hereditary hemochromatosis is tightly associated with mutations within the hemochromatosis gene (HFE gene). More than 93% of Irish patients are found to be homozygous for the HFE gene C282Y mutation.

Experts recently found such a mutation in the remains of two ancient people—a Bronze Age woman who lived about 5,000 years ago and an early Neolithic man who lived about 4,000 years ago. The woman had one of the gene variants responsible for hemochromatosis. Meanwhile, the man had a different mutation that has been associated with a more severe form of the disease that is most common in people of European ancestry.