BRCA genes are called tumour suppressor genes as they control cell growth, but when they contain abnormalities or mutations, they no longer function normally and the risk of breast and ovarian cancer increases.
Only around one in 20 women who develop breast cancer does so because they have inherited a faulty gene, according to Cancer Research UK.
Professor Peter Johnson, the charity’s chief clinician, said: “It’s important women who carry these genes know there are now things they can do to reduce their risk.
“Having surgery is just one of several options – they can also have regular monitoring and screening.”
Anyone with concerns should contact their GP.