Editor’s note: Pending an FDA decision, 23andMe no longer offers new customers access to health reports referred to in this post. Customers who purchased prior to November 22, 2013 will still be able to see their health reports, but those who purchased after that time will not. Those customers will have access to ancestry information as well as access to their uninterpreted raw data.
It’s the most common genetic disease you never heard of. Hemochromatosis, sometimes called the “Celtic Curse,” affects an estimated one in every 300 Americans, but many who have it have no idea they do.
July is National Hemochromatosis Month, and 23andMe will be highlighting stories and research related to this genetic disease which can quietly lead to iron overload — a serious medical condition — over time. Some people may never know they have the problem because the symptoms often appear later in life — between the ages of 40 and 60 in men and after menopause in women. But iron overload can cause serious damage to the liver, kidney, heart and other organs. When iron levels in the body become dangerous, lowering those levels can be done relatively simply by having blood drawn regularly. Changes in diet can also help maintain safe levels and avoid the problems caused by chronic high levels of iron.
There are several forms of hereditary hemochromatosis. 23andMe currently reports on two of the most common genetic variants in the HFE gene that can lead to the condition — C282Y and H63D. Mutations in other genes can cause other kinds of hereditary hemochromatosis.
Up to 90 percent of those with hereditary hemochromatosis have two copies of the most severe variant in the HFE gene — C282Y — and they are at the highest risk of developing iron overload, though not everyone develops symptoms and environmental factors also effect iron levels. Individuals with one copy of the C282Y variant and a second, milder variant in the HFE gene are also at some risk for iron overload, though they are less likely to end up with organ damage.
The Centers for Disease Control notes that early detection of the disease is important, but diagnosing it can sometimes be difficult. Knowing your family history and whether you have a genetic risk for the disease can help you and your doctor decide whether you should be more proactive in screening for the condition, which can be easily managed.