MONDAY, Feb. 12 (HealthDay News) -- Extensive genetic analysis has uncovered a gene variant that cuts the risk of breast cancer by 10 percent, scientists say.

Angela Cox, senior lecturer at the Institute of Cancer Studies at the University of Sheffield, U.K., led the study, which included more than 30,000 women and 20 research groups from every corner of the globe, from the United States to Australia, Finland to Singapore.

The group -- called the Breast Cancer Association Consortium -- tested genetic variants, called "single nucleotide polymorphisms," from nine different genes that previously had been implicated in breast cancer through small-scale studies. Most of the studies involved women of European descent, in whom the risk of breast cancer is about one-in-nine.

"This study aimed to confirm or refute those previous reports by doing a big study with good statistical power to determine which of these nine [genes], if any, were really associated with breast cancer," Cox said.

The team found "strong statistical evidence" that one variant, a single amino acid change in the CASP8 gene, was associated with a small reduction in breast cancer risk in European women. Carrying this genetic variant decreased a woman's risk of disease by 10 percent, lowering her risk from one-in-nine to one-in-10, Cox said.

The findings were published Sunday in the journal Nature Genetics.

Another genetic variant in the TGF-beta1 gene, had a "slightly weaker association," Cox said, increasing the risk of disease by 7 percent, and the other seven showed "no or only marginal evidence" of being associated with breast cancer.

"This study demonstrates how genes that confer modest effects on breast cancer risk can be identified when sufficiently large data sets are assembled," said U.S. National Cancer Institute Director Dr. John E. Niederhuber, in a written statement. "Analyses of this type should help accelerate our ability to target the right genes for very specific subsets of disease."