Researchers find new gene linked to breast cancer

In collaboration with the Press Association

Researchers have identified a new gene that, if faulty, may increase a woman's risk of breast cancer by more than a third. The gene, called HMMR, was also found to interact with the well-known breast cancer gene BRCA1. Faults - or mutations - in either gene interfere with cell division, and cause the cell's chromosomes to become unstable. This can lead to the development of breast cancer. "If we can identify variations of genes that are more common in the population that increase breast cancer risk, then targeting that gene for early detection or treatment will have a greater impact," said Kristen Stevens, a doctoral student in epidemiology at the University of Michigan School of Public Health and one of the lead researchers. The HMMR gene is mutated in about one in ten of the population, while faults in BRCA1 and BRCA2 occur in about one of every 300 people. Researchers discovered that HMMR was a key player in the development of breast cancer by developing a computer tool that allows a large amount of scientific data from a range of sources to be analysed easily. This enabled them to spot genes that are involved in the development of cancer. The researchers first studied the genes BRCA1, BRCA2, ATM and CHEK2 as they are already known to play a role in breast cancer. They were then able to see how each of these genes interacts with other genes in the body, and from this discovered that HMMR has a role in breast cancer development. Changes in either BRCA1 or HMMR were then shown to lead to chromosome instability and interfere with cell division. Following this discovery a total of 2,475 women with breast cancer and 1,918 healthy women were studied in Israel and New York. From this, the researchers found that the risk of breast cancer was 23 per cent higher in women who had one copy of the faulty version of HMMR, and 46 per cent higher in women who had inherited two copies. In addition, those women were diagnosed with breast an average of 12 months younger than women from the control group, suggesting that HMMR is linked to early-onset disease. The study was published in the journal Nature Genetics. Author Laura Rozek, a postdoctoral research fellow at the University of Michagan Medical School, explained the significance: "Identifying genes involved in cancer in the general population is important, because not all of the causes of breast cancer have been found. Through discoveries such as this, someday we might be able to more precisely estimate a person's risk of cancer based on their genes."