New Gene Linked to Breast Cancer Found

A study of Jewish women in Israel discovered a new gene that, if mutated, may increase a woman’s risk of developing breast cancer by more than one-third.

The study of 923 Jewish women with breast cancer and similar women without breast cancer — Ashkenazi Jewish women carry a higher risk of breast cancer than other ethnicities — found the gene HMMR interacts with the well-known breast cancer gene BRCA1. Alternations in either gene cause genetic instability and interfere with cell division, which could be a path to breast cancer developing, explained study leader Dr. Gadi Rennert director of the CHS National Cancer Control Center in Haifa, Israel.

Rennert and researchers from Spain and several centers in the United States say HMMR is mutated in about 10 percent of the population, while mutations in the two main genes involved in breast cancer susceptibility, BRCA1 and BRCA2, occur in about one of every 300 individuals, or less than 1 percent of the population.

The study, published in the online edition of Nature Genetics, found women with a variation in the HMMR gene had a higher risk of breast cancer. Even after accounting for mutations in the BRCA1 or BRCA2 genes, the risk of breast cancer in women under age 40 who carry the HMMR variation was 2.7 times the risk in women without this variation.