Analysis: Genetics is thought of as inheriting traits like eye colour or height but there are other things you might inherit that are not visible on the surface, and yet could greatly impact your life.

We all get the basis of genetics and inheritance. You see it in the people around you – perhaps you inherited your Dad's height, or your Mum’s hair. It’s the reason why you could use your sister’s ID to get into that pub a few years back – but there are other things you might inherit that are not visible on the surface, and yet could greatly impact your life.

In May 2013, headlines hit media outlets about actress Angelina Jolie, but these stories didn’t cover her newest movie or directing gig. Instead, they focused on a recent surgery she had undergone in a bid to help prevent cancer from developing in her body at an early age.

Angelina Jolie’s decision was to have a preventative double mastectomy, a surgery which removes all breast tissue, with optional breast reconstruction.

This choice was made on the back of the fact that at the time, the 37-year-old had been identified as carrying a BRCA1 genetic alteration, following her mother passing away from cancer at 56 years of age.

What is BRCA?

The term 'BRCA1/2’ comes from ‘breast cancer 1 or 2’ genes. Everyone has these genes, and when healthy, they act primarily as tumour suppressors, which means that they help in preventing cancerous growths. Sometimes these genes can be faulty, or become ‘altered’ – and in this state, BRCA1/2 genes no longer function as normal.

In this case, this alteration in BRCA1/2 genes lead to much higher risks of developing certain cancers in a person’s lifetime, and these risks increase with age.

As this alteration in BRCA1/2 is genetic, if one parent has a BRCA1/2 alteration, there is a 50% chance that their child will also inherit the altered gene and have the same increased lifetime risk of developing cancer.

We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences

From RTÉ Radio One's Liveline, more listeners talk about breast cancer.

Increased Cancer Risk

The exact percentage of increased cancer risk differs between the sexes, as do the types of cancer that are impacted.

For females, someone with a BRCA1 alteration has a 60 – 90% chance of developing breast cancer in their lifetime, and those with a BRCA2 alteration have a 45 – 85% chance. For ovarian cancer, females with a BRCA1 alteration have a 40 – 60% lifetime risk, and for BRCA2, this is 10 – 30%.

In men with a BRCA1 alteration, they have a 0.1 – 1% chance of developing breast cancer in their lifetime, and around a 10% risk of developing prostate cancer – these are risks considered to be similar to the general male population. Those with a BRCA2 alteration have an increased risk of 5 – 10% of developing breast cancer, and 20 – 25% of prostate cancer in their lifetime.

Risk Reduction

As with Angelina Jolie, females can choose to have preventative surgeries to reduce their cancer risk by removing parts of the body that are at high risk of developing cancer.

This process usually involves removing both the ovaries and fallopian tubes to reduce the risk of ovarian cancer, called a salpingo-oopherectomy, and a double mastectomy to reduce the risk of developing breast cancer.

Another choice to stay on top of cancer risk can be to go for regular screening appointments, such as mammograms or ultrasounds for breast screening. There are currently no adequate screening measures to monitor ovarian cancer.

We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences

From RTÉ Radio One's The Ryan Tubridy Show, Claire Hayden spoke to Ryan last year having just been diagnosed with breast cancer. This morning Claire joined Ryan on the line with an update on how her year has been and the importance of friends, family and keeping positive throughout it all.

Things to Look Out For

If there are a lot of cases of cancer in your family, you might wonder whether it is appropriate to get genetic testing. To do so, your GP can take a family tree and decide with you whether or not to refer you forward for genetic testing. The test itself takes the form of a blood sample – this is then sent for analysis.

Some key pointers that suggest it would be beneficial for testing are if you or a family member had breast cancer diagnosed before 45; any incidence of male breast cancer; or that one side of the family has multiple cases of breast/ovarian/prostate cancer, especially if these occurred at a young age.

This is not an exhaustive list, however, the presence of these might indicate that it would be worth raising genetic testing with your GP. Direct to consumer tests, such as ‘23 and Me’ are not advisable as they do not offer thorough, medical-grade testing.

The Family

Identifying a BRCA1/2 alteration has far-reaching consequences for the individual being tested, and for their family. Finding out about a BRCA1/2 alteration can cause a variety of psychological responses and some find it particularly empowering as it allows them to make informed decisions about their health.

In some cases, it can lead to psychological distress as the news of the gene alteration is shared amongst family members. Sometimes, people can feel distress surrounding the fear of them or a family member developing cancer, or for females, about having to decide on how to try to reduce risk.

Talking to children about the risk present in the family can be particularly difficult. It is up to each family how to handle this discussion, some choose to start the conversation from a young age, others may wait until an age they deem suitable.

In general, it is recommended that parents tailor any information that they want to share with their children to be age-appropriate.


The views expressed here are those of the author and do not represent or reflect the views of RTÉ