Gene Flaws for 3 Cancers Isolated by Researchers

Researchers probing the genetic mutations that make some people more susceptible to cancer than others have isolated specific gene flaws for leukemia and for breast and kidney cancer.

In studies published Tuesday in the Journal of the American Medical Assn., scientists report they have moved closer to being able to identify at a very early age those patients who have inherited specific genes that might lead to cancer later in life.

The discoveries could lead to laboratory blood tests that would enable the patients to be counseled on their cancer liability and help clinicians make decisions about early treatment or about procedures that could prevent the disease, experts said at a news conference.

Researchers at nine centers who are searching through the DNA of the BRCA1 gene, which is known to increase susceptibility to breast and ovarian cancer, have now found 57 mutations related to the diseases.

Mark H. Skolnick of the University of Utah School of Medicine said the BRCA1 gene may have as many as 200 mutations that lead to the cancers.

“The gene is very large and these mutations are spread across the whole gene,” he said. “There is no clustering.”

Of the 57 mutations, Skolnick said, only three seem to be common.

The mutations were found in about 7% of 1,086 breast and ovarian cancer patients tested at U.S. and British laboratories.

Skolnick said that once all the mutations have been identified, a process that may take two years, researchers will determine which of these genetic flaws can lead to cancer and which are neutral.

Then, he said, researchers will be able to develop tests that identify patients with a high risk of breast or ovarian cancer.