These findings made us wonder whether HMMR might also be a breast cancer susceptibility gene, says study author Stephen Gruber, M.D., Ph.D., M.P.H., the H. Marvin Pollard Professor of Internal Medicine at the U-M Medical School. Gruber is an associate professor of internal medicine and of human genetics in the U-M Medical School, and of epidemiology in the U-M School of Public Health. He directs the Cancer Genetics program in the U-M Comprehensive Cancer Center, which focuses on inherited cancer risks.
To understand whether variation in HMMR increases breast cancer risk, the researchers looked at the genes of 923 Jewish Israeli women with breast cancer and similar women without breast cancer in a study led by Gadi Rennert, M.D., director of the CHS National Cancer Control Center in Haifa, Israel. The Ashkenazi Jewish population in Israel carries a higher risk of breast cancer than other ethnicities.
This component of the study found that 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. In particular, 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.
The researchers further verified the finding in a second group of Ashkenazi Jewish women in New York who had a family history of breast cancer but no identified BRCA1 or BRCA2 mutations and a third study of Jewish women with and without breast cancer in New York. In total, 2,475 women with breast cancer and 1,918 healthy women were studied in Israel and New York.
Overall, the risk of breast cancer was 23 percent higher in women who had one copy of genetic variant, and 46 percent higher in women who had inherited two copies. In addition, those women were diagnosed an average of 12 months younger than women from the control
|Contact: Nicole Fawcett|
University of Michigan Health System