Genetic Link to Hereditary Cancer Traced to Quebec Ancestor

Researchers have uncovered new insights into the most prevalent genetic mutation associated with hereditary cancer in Quebec's French-Canadian community. Using genetic data from the CARTaGENE cohort and genealogical records from the BALSAC database, scientists traced a specific variant back approximately 11 generations to a single ancestor. They estimate that around 1 in 800 French-Canadians carry this mutation, with higher incidences in regions including Charlevoix, Côte-de-Beaupré, Saguenay–Lac-Saint-Jean, Beauce, and Côte-du-Sud.

This genetic variant is linked to Lynch syndrome, a condition significantly increasing the risk of colorectal and other types of cancers. Originally identified in 2008 within a Quebec family affected by Lynch syndrome, its widespread presence across the population and origin was previously unknown. The study, published in 11cge, provided by McGill University researchers, leverages both clinical data and historical records to deepen understanding of Quebec’s genetic landscape.

Senior author Simon Gravel from McGill emphasized how combining clinical information with historical records can clarify genetic risks, while Dr. William Foulkes highlighted the practical implications. He suggested that the high prevalence of this mutation could enable the design of low-cost genetic tests targeting a handful of variants, potentially detecting up to 50% of inherited cancers in the region.

Early detection of colorectal cancer is crucial, as it is often treatable when caught early. The study's findings pave the way for improved screening strategies that could save lives and reduce healthcare costs in Quebec's population.

For more details, the full study is accessible in 11cge with DOI: 10.1111/cge.14784.