Scientists have discovered two new gene variants associated with an increased risk of breast cancer, a major new study says, providing important insights into the causes of the disease and how it develops.
An international team of researchers, led by the Institute of Cancer Research, is credited with the find after analyzing the DNA of approximately 86,000 women of European, 12,000 of Asian and 2,000 of African ancestries, around half of whom had breast cancer.
Using a state-of-the-art genetic technique called "fine mapping," they searched for one-letter differences in DNA code that were more likely to be found in women with breast cancer than those without the disease.
They ended up identifying two genetic variants on chromosome 9. One is called rs10816625, and increases a woman's risk of developing breast cancer by 12 percent. The second variant, rs13294895, increases a woman's breast cancer risk by 9 percent. The research team believes both variants help control the activity of KLF4 - a gene thought to help control the way cells grow and divide.
The genetic variants are also specifically linked to the most common form of breast cancer, oestrogen receptor positive. Increased risk for this type of breast cancer was slightly higher - 14 percent and 11 percent, respectively - if these variants were present.
"Our study zoomed in on an area of our genome that we knew was linked to breast cancer risk, and has identified two new genetic variants that add significantly to our knowledge about the genetic causes of the disease," study leader Dr. Nick Orr, at The Institute of Cancer Research in London, said in a press release.
"The more genetic risk factors for breast cancer we discover," he added, "of which there are currently more than 80, the more accurately we will be able predict who is at risk of getting the disease. Ultimately this will be vital for designing preventative strategies against breast cancer."
Aside from lung cancer and certain types of skin cancer, breast cancer is the most common cancer in all women, according to the Centers for Disease Control and Prevention (CDC). And by screening for all known genetic variants, including those just discovered, scientists hope to identify which women are most at risk of the disease and eventually improve prevention strategies.
The results were published in the journal Human Molecular Genetics.
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