What is the BRCA gene?

couple geneticsEver since the first ‘test tube baby’ was born back in 1978, we’ve seen incredible advances in fertility treatments, which has resulted in thousands of babies for otherwise infertile couples. One of those advances is the ability to screen for genetic mutations and chromosomal abnormalities that may eventually develop into a disease like breast cancer.

Well, although we’re still figuring out just what the relationship between genetics and the chances of developing breast cancer, a child born without the BRCA gene will not develop a certain form of breast cancer later in life because the gene is not present and therefore cannot mutate. As you may have deduced, the BRCA gene is otherwise known as a ‘breast cancer gene.’

There are really two different ‘breast cancer genes’ – the BRCA-1 and the BRCA-2 – and they both significantly increase a woman’s risk of developing breast cancer when mutations are present. It is important to note, however, that not all women with these mutations go on to develop breast cancer and not every type of breast cancer is caused by these genetic mutations.

Since we’ve played a role to eliminate the BRCA-1 gene, let’s talk a little more about it. It was discovered in 1990 and is found on chromosome 17. A mutation of this gene increases the risk of breast and ovarian cancer, but also pancreatic cancer. However, a BRCA-1 gene may also mean a person has a higher risk of cervical, uterine, and colon cancer.

Everyone has BRCA genes naturally, and when they are normal, they act as tumour suppressors, which means they help regulate cell growth at a normal rate. Mutations in these genes may cause cells to develop abnormally, which is cancer in the simplest of terms.

The mutations of the BRCA genes are passed down from parent to child, but we get two copies – one from Mum and one from Dad. Therefore, if a harmful mutation is on one of the genes we inherit, every cell in our body will have one normal gene and one mutated gene. As long as the normal copy maintains normal function, there will be no breast cancer. That’s why even with a BRCA mutation a woman may not actually develop breast cancer, though she is at higher risk.

So, now that you know what the BRCA gene is, you should be as excited as we are to know that we’ve been able to eliminate it and potentially save lives down the road.