Genotype plus an affected relative tied to increased risk.

2002 OCT 24 - (NewsRx.com & NewsRx.net) -- Researchers have identified a genotype associated with women who have recently diagnosed breast cancer and who claim a first-degree relative (mother and/or sister) with the disease. For women age 50 or younger at diagnosis, the link is even stronger.

"Women in the United States whose mother or sister has had breast cancer have twice the risk of developing the disease by age 85 as women in the general population," noted Eldon R. Jupe, PhD, immunobiology and cancer program, Oklahoma Medical Research Foundation, Oklahoma City. "But our study now shows that women with both the prohibitin T allele, one of two forms of the prohibitin gene that can occupy the chromosomal slot we investigated, and an affected first-degree relative have an almost five-fold higher risk."

In breast cancer cell lines, Jupe's previous research has shown that one location on the prohibitin gene is often altered. His research team found that this altered region gives rise to two alleles, referred to as C and T. The C variation codes for an RNA molecule that interferes with the cell cycle and has been shown to suppress tumor growth in animals; the T variation is functionally inactive.

Based on this finding, Jupe and his team compared prohibitin genotypes in 205 patients and 1046 control subjects. This ...