Rare form of hereditary colon cancer identified

Scientists have identified a new rare form of hereditary colon cancer that is caused by a genetic mutation that was previously unknown.

The formation of large numbers of polyps in the colon has a high probability of developing into colon cancer. The appearance of polyps is often due to a hereditary cause and the disease can occur in multiple family members. Researchers from University Hospital Bon-n in Germany discovered genetic changes in the MSH3 gene in patients and identified the rare form of hereditary colon cancer. Colon polyps form like mushroom-shaped growths from the mucosa and are several millimetres to centimetres in size. They are benign and generally do not cause any symptoms — however, they can turn into malignant tumours (colon cancer).

Physicians refer to the development of a large number of polyps in the colon as “polyposis.” Scientists have already discovered several genes associated with a polyposis. “However, about one-third of families affected by the disease do not have any abnormalities in these genes,” said Stefan Aretz, from the University of Bonn Hospital. Researchers, including those from the Yale University in the US, and the Frankfurt University Hospital, studied the genetic material (DNA) of more than 100 polyposis patients using blood samples.

In each patient, all of the about 20,000 protein-coding genes known were examined. Scien-tists found the rare, possibly relevant genetic changes out of the gigantic quantity of data.