US inherited bowel cancer risk traced back to immigrant couple
Researchers have discovered that a married couple who travelled from England to the US in the 1630s could be responsible for hundreds of modern-day people being at risk of a hereditary form of bowel cancer.
Experts at the University of Utah traced a specific gene fault linked to increased bowel cancer risk that is found in two large families in Utah and New York.
They found evidence that the mutation originated in the couple who moved to the US in the 17th century, around the time of the Pilgrims.
This 'founder' mutation causes a condition called attenuated familial adenomatous polyposis (AFAP) which, if not treated, greatly increases the risk of bowel cancer.
The mutation is thought to contribute to a significant proportion of bowel cancer cases in the US, yet effective screening can help to prevent the disease.
Lead researcher Dr Deborah Neklason, a research assistant professor at the University of Utah, commented: "The fact that this mutation can be traced so far back in time suggests that 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 (bowel) cancer cases in the United States."
The Utah family involved in the study contains more than 7,000 descendents, who account for 0.15 per cent of all bowel cancer cases in the state between 1966 and 1995. Estimates suggest that, by identifying the family as being at risk and taking preventive action, just one family member with the gene fault went on to develop bowel cancer during those years instead of the expected eight cases. "Preventing seven cancers may not sound like much, but that's seven colon cancers that didn't devastate this family," said Dr Neklason.
The researcher emphasised that diagnosing AFAP can be "life-saving" and urged people to discover their family cancer history and discuss the information with their doctor.
"Doctors need to be aware of AFAP, recognise people at risk, and know the screening and treatment protocols that can prevent colon cancer from developing," she said.
The findings are published in Clinical Gastroenterology and Hepatology journal.