It is known that breast cancer runs in families, but apart from a few rare, highly penetrant variants that account for less than 25 percent of the hereditary risk, most genetic risk factors are unknown. Researchers think the remainder of the genetic risk could be explained by a number of relatively common genes, each with a small effect, working in combination with each other.
To find out more, researchers conducted a study in a population of European descent, examining the genomes of 4,554 affected individuals and 17,577 controls, and replicated the results with five other groups. They found that the 25 percent of women who had two copies of a variant on chromosome 2q35 had a greater risk for breast cancer than those without it. Seven percent of the women in the study who had two copies of a variant found on chromosome 16q12 had a greater breast cancer risk than non-carriers.
More: To read an abstract of this paper on PubMed, a medical database, click here.