Four novel breast cancer susceptibility genes are identified in a study published online in Nature. The large, genome-wide association study also points to many more genetic markers that should be pursued for their link to the disease. Together with two related papers online in Nature Genetics, these findings increase our knowledge of the genetic component of breast cancer risk, much of which has remained uncharacterised.
Known susceptibility genes - such as BRCA1 and BRCA2 - account for less than 25% of the familial risk of breast cancer. It is believed that a combination of many additional genetic factors, each playing a smaller role, also contribute to the disease. To look for further susceptibility alleles Douglas F. Easton and colleagues conducted an analysis, as part of which 30 single nucleotide polymorphisms (SNPs) were tested in 21,860 patients and 22,578 controls. The authors identify four genes positively associated with genetic susceptibility to breast cancer (FGFR2, TNRC9, MAP3K1 and LSP1). Further investigation indicates that many additional susceptibility alleles of more modest effect may also be identifiable by this approach.
Most previously identified breast cancer susceptibility genes are involved in DNA repair, but the associations reported here appear to relate more to the control of cell growth or to cell signalling. Only one of the genes - FGFR2 - had a clear prior relevance to breast cancer.
In Nature Genetics, two studies provide further evidence of the risk for breast cancer. One paper, from David J. Hunter and colleagues, identifies alleles for the gene FGFR2 as being particularly associated with the risk of sporadic postmenopausal breast cancer. Another paper, from Simon Stacey, Kari Stefansson and colleagues, reports genetic variants on each of chromosomes 2 and 16, which both increase the risk of oestrogen-receptor-positive breast cancer. One of these variants is located in close proximity to the gene TNRC9, which was also identified in the study from Easton and colleagues.
Douglas F. Easton (University of Cambridge, UK).
Please contact this author through:
Emma Gilgunn-Jones (Press Officer, Cancer Research UK, London, UK)
David J. Hunter (Harvard School of Public Health, Boston, MA, USA)
Kari Stefansson (deCODE Genetics, Reykjavik, Iceland)
Simon Stacey (deCODE Genetics, Reykjavik, Iceland)
You may also contact the above 2 authors:
Edward Farmer (Director of Corporate Communication, deCODE Genetics, Reykjavik, Iceland)
Abstracts available online:
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Message posted by: Trevor M. D'Souza