Research at Women’s College Hospital has discovered a genetic mutation strongly linked to hereditary breast cancer among two groups of Canadian women — those of French-Canadian and Polish extraction. The cause of this mutation appears to lie with the so-called founder effect, a dramatic genetic drift that occurs when a new population is created (as in Canada) based on a relatively few individuals known as founders. The Canadian-Polish research team found recurrent mutations in a gene known as RECQL gene among women of Polish descent. Notably, these women did not carry any of the better known breast cancer genes. Researchers also found also that a variation on the RECQL mutation occurred 50 times more frequently among Quebec women with familial breast cancer compared to control subjects. Another RECQL mutation put affected Polish women at a five-fold increased risk for developing breast cancer compared to women without the mutation. While RECQL mutations appear to be quite rare, researchers estimate that up to half of all women who have the mutation will get breast cancer.
