Colon cancer mutation traced to 1630

Utah cancer researchers have traced a hereditary form of colon cancer back to a married couple who arrived in America from England around 1630.

Using two large families — one in Utah and another in New York — that carry an identical gene mutation that increases risk of colorectal cancer, the Huntsman Cancer Institute-led team followed the genealogy back to discover what they call a "founder mutation," which is one shared by a common ancestor and believed to have begun with that individual, in this case one of the couple.

The HCI researchers believe it's an important finding because, over the generations, there are likely many other descendants who are at risk of the cancer and in need of early screening and education.

"This founder mutation might be related to many colon cancer cases in the United States," says Deb Neklason, Ph.D., research assistant professor at HCI and the lead author.

The findings were published today in the journal Clinical Gastroenterology and Hepatology.

The mutation is responsible for a condition called attenuated familial adenomatous polyposis (AFAP). People who have the mutation have a 67 percent chance of developing the cancer if they are not screened and the disease prevented, while just less than 4 percent of the general population develop colon cancer. AFAP also generally strikes at a younger age, around the mid-50s, compared to an average age in the early 70s for other colon cancers.

Neklason said the mutation-related colon cancer has even been found in people in their 20s, while the precursor polyps may begin appearing in the late teens.

Each child of a parent who carries the mutation has a 1 in 2 chance of inheriting it. But with proper care and education, it need not lead to cancer.

The researchers used the Utah Population Database, a massive database that links genealogical records with many public records, including those of births and deaths, as well as medical data. It's used to identify for study the families that have an unusually high incidence of cancer and other diseases, to look inheritance patterns and to find genetic mutations.

All research is done without identifiers, although data can be linked so that the individuals can be given information that's important for their health or can be invited to participate in research projects.