Well, actually there are two BRCA (pronounced "Brakka") genes: BRCA1 and BRCA2. Few genes have caused so many headlines in recent years as they did. The BRCA genes are so hotly debated as an American biotech company was holding an extremely lucrative patent on these two genes. What that means I would like to explain later; but first, why are BRCA1 and 2 so important?

BRCA is an abbreviation for breast cancer and that is the very important context of those genes. As is often the case, the starting point for the discovery of BRCA genes was a serious illness. There are ways to compare DNA sections within the genome of patients suffering from a disease as compared to healthy controls. When, in the late 1980s, large groups of patients (in this case breast cancer patients) began to be compared with control groups in this way, a small section was found on chromosome 17 in which certain sequence variants were associated with the disease. In this section, the BRCA1 gene was identified in the mid-1990s.

The protein encoded by BRCA1 plays an essential role in DNA repair. Radiation, mechanical irritation or simply statistically (very rarely) occurring errors in the handling of the cell with the DNA can cause so-called double-strand breaks, i.e. both DNA strands break, leaving a gap in the double helix. This is a very serious event for the cell and it responds by activating a rescue program. BRCA1 and BRCA2 are involved in a network that after such a break captures the open DNA ends on the other copy of the DNA segment (we always have two: one from the mother, one from the father). They then read this area and reassemble the open pieces of the damaged strand according to what they have just read on the non-damaged strand. If these genes are defective, there will be more errors in DNA repair and thus mutations. The more mutations you accumulate, the higher the risk of developing cancer.

While a 25-year-old woman with intact copies of BRCA genes has a 84% chance of becoming 70 years or older, this probability is reduced to 53% (in the case of BRCA1) and 71% (in the case of BRCA2) when women carry a mutation in those genes. Of course, this only applies if no cancer prevention measures are taken. For Angelina Jolie, who carries two broken BRCA1 copies, this was reason enough to have both breasts amputated. Any other woman must also decide for herself: first, whether a genetic test for the BRCA genes is advisable for her and given any positive test results, what steps to take then. 

Well, the actual costs of such a test on just two genes, are actually quite low. However, with the BRCA genes, a US biotech company called Myriad Genetics had a patent on these genes and thus the sole right to offer these tests. This would cost, depending on the accuracy of the investigation, from $ 500 to over $ 5000 per person. Logically, many patients, doctors as well as competing companies are not happy with this situation and so this yearlong dispute arose over the dubious patent. In 2013, the US Supreme Court finally took the overdue step and generally declared that the patentability of human genes, as products of nature, was inadmissible.