The most powerful genetic analysis of the DNA codes of over 40,000 women -- including those with breast cancer as well as those without the disease – has uncovered five common genetic variants that increase an individual’s risk for breast cancer.
In a paper published online today in the journal Nature, the international team of scientists who conducted the genome-wide association study report that these five genes code for proteins crucial to biological activities that previously had not been implicated as triggers of breast cancer. The genes carry the DNA recipes for proteins important to the growth and duplication of body cells and the signalling, or communications, that must occur between cells in order for the body to function normally.
Previous investigations have identified about a dozen genetic mutations associated with breast cancer susceptibility. Normal versions of these genes help prevent cancer from occurring in the first place, by helping cells to repair DNA breaks and other abnormalities that can result from chance or exposure to an environmental toxin, such as excessive UV sunlight. However, BRCA-1, BRCA-2 and the other previously identified breast cancer susceptibility genes are mutated in a relatively small percentage of women.
"Risk mutations within these genes are so rare that only a very small number of breast cancer incidences are caused by these mutations," said Jianjun Liu, Ph.D., co-author of the Nature paper and Senior Research Scientist at the Genome Institute of Singapore, one of the over 20 research institutions collaborating in the international study of breast cancer genes.
The five genetic variants identified by Dr. Liu and collaborators occur more frequently among women with breast cancer than do BRCA and the other previously identified breast cancer susceptibility genes.
The five genes are the FGFR2, TNRC9/ LOC643714, MAP3K1, and LSP1.
"This is a truly landmark breakthrou
Source:Agency for Science, Technology and Research (A*STAR), Singapore