US colon cancer risk blamed on English couple
Founder genetic mutation fingered
US researchers have identified a married couple who sailed from England to the US in around 1630 as the bearers of a genetic mutation which puts their numerous descendants at higher risk of a hereditary form of colon cancer.
Reuters explains that cancer researchers at the Huntsman Cancer Institute in Utah began to look into a local "family", currently numbering about 5,000 people, "because its members had an unusually high risk of colon cancer". Over 14 years they scoured detailed Mormon church records, in the process identifying another group in New York at similar risk. The genetic trail from both eventually led back to the British pair.
Study leader Deb Neklason said: "The fact that this mutation can be traced so far back in time suggests it could be carried by many more families in the United States than is currently known. In fact, this founder mutation might be related to many colon cancer cases in the United States."
The mutation in question provokes "attenuated familial adenomatous polyposis" (AFAP), which makes people "more prone to developing polyps that can cause colon cancer". In the absence of adequate treatment, the carriers are at a "greater than 2 in 3 risk of developing colon cancer by age 80, compared to about 1 in 24 for the general population".
Neklason concluded: "This study highlights that you need to pay attention to your family history. With intervention to remove the polyps, the risk goes to near nothing."
The study on the unnamed families is published in Clinical Gastroenterology and Hepatology. ®
Colorectal cancer is the "third-leading cause of cancer death in the United States" and will kill 52,000 people in the US in 2008, according to the American Cancer Society.