Breast Cancer :: Low-risk breast cancer gene found

Two mutations in the gene for a rare genetic disorder appear to be associated with an increased risk of breast cancer, a new study suggests.

Ataxia-telangiectasia is an autosomal recessive disorder that results from the inheritance of two defective copies of the ATM gene. Previous studies have suggested that carriers of a single defective copy of the gene are predisposed to various cancers, but its link to breast cancer risk is still in question.

In the Feb. 6 issue of the Journal of the National Cancer Institute, Georgia Chenevix-Trench, Ph.D., at the Queensland Institute of Medical Research, Australia, and colleagues report that two specific mutations in the ATM gene were associated with breast cancer in women from multiple-case breast cancer families.

The authors conclude that ?full mutation analysis of the ATM gene would be worthwhile in other multiple-case breast cancer families … to clarify further the role of this gene in breast cancer susceptibility.?

“This is definitely the first absolutely validated and confirmed low-risk gene for breast cancer,” Dr Chenevix-Trench said.

“We’ve been looking for these kinds of genes for years, with thousand of options put forward, and now we have one that’s definitely real.”

It has no immediate implications for women with breast cancer, because there would be little use in testing for that one gene alone.

But Dr Chenevix-Trench said researchers expected to unearth other similar genes which women could eventually be screened for.

“My guess is that we’ll have a handful of them confirmed with the same degree of confidence within the next year or two,” she said. “After that we can start to think about testing protocols to see whether it’s worth identifying women who have multiple variants like this.

“Simply having one of them is not enough but if you’ve got five or six of them in different genes those are women who might be targeted for earlier and more intensive screening.”

Researchers studied nine genes believed to have links to breast cancer and tested the claims on more then 20,000 women from Australia, the US and Europe, half of whom had breast cancer.

The results, published in the journal Nature Genetics yesterday, reported that eight had either no or marginal evidence of a link, with only Caspase 8 standing up to robust investigations by the 20 research groups.


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