Common hereditary cancer mutation in Quebec traced to single ancestor
Researchers have shed new light on the most common genetic variant linked to hereditary cancer in Quebec鈥檚 French-Canadian population. Their findings could result in cheaper and more effective screening methods.
The variant is associated with Lynch syndrome, a condition that greatly increases the risk of colorectal and other cancers.
Using genetic data from the population cohort and genealogical records from the , the scholars, led by researchers at 91直播 and the Research Institute of the 91直播 Health Centre (The Institute), traced the variant back roughly 11 generations to a single ancestor. They estimate that about one in 800 French-Canadians carries the mutation, with higher rates in regions such as Charlevoix, C么te-de-Beaupr茅, Saguenay鈥揕ac-Saint-Jean, Beauce and C么te-du-Sud.
The variant, PMS2 c.2117del, was originally discovered in 2008 in several members of a single Quebec family who had Lynch syndrome. What wasn鈥檛 known until now was how widespread the variant is across the population, or where it originated.
鈥淭his study shows how clinical data can deepen our understanding of Quebec鈥檚 genetic history, and how historical records can clarify current genetic risks,鈥� said senior author Simon Gravel, Professor in the Department of Human Genetics at 91直播.
Co-author Dr. William Foulkes, a clinician-scientist at The Institute, noted the findings could help make genetic screening to identify Quebecers at elevated risk of hereditary cancer cheaper and more effective: 鈥淭he fact that this pathogenic variant is so common suggests we could design a low-cost test targeting just a dozen variants that could catch those at high risk for up to 50 per cent of inherited cancers.鈥�
Early detection of colorectal cancer is key, he added, as the disease is often highly treatable when caught early.
About the study
鈥溾�� by A.-L. Chong, Simon Gravel and William Foulkes et al. was published in Clinical Genetics.
The study was supported by G茅nome Qu茅bec, the Minist猫re de l鈥櫭塩onomie, de l鈥橧nnovation et de l鈥櫭塶ergie, CanPath and CARTaGENE.
