Advice needed about breast cancer gene

[CalJo]

Hi

I was wondering if anyone could give me any advice about some kind of gene that can make you more likely to develop breast cancer.

My cousin on my mothers side has recently been diagnosed with breast cancer for the second time so she was tested for a gene that can cause someone to be more susceptible to breast cancer and she has tested positive for the gene.

I generally don't have much to do with my Mums side of the family so I am left a bit in the dark as to whether this would have any affect on me. I have looked through the net to understand but can't decipher if I could be potentially affected by this or not and if I am what would I do about it?

Any advice would be appreciated.

Thanks

Need to talk to your GP & your cousin. Which gene was it.

There are gene mutations that make you more likely to develop breast cancer and how they are inherited depends on the specific mutation. The most common are BCRA 1 and BRCA 2. Each person has two copies of the every gene. Mutations are when the healthy gene has changed and now causes a problem. The BRCA mutations are autosomal dominant mutations, which means you only have to have one copy of the mutation to make the cancer more likely.

Whether you could have the gene depends on whether your cousin inherited it from her mother or father, or whether the mutation happened in her cells first (a de novo mutation). As she is a maternal cousin, if she inherited it from her father or if it was a new mutation, you are at no more risk of it than the general population.

If she inherited it from her mother, her mother must carry the mutated gene. If her mother, your aunt, has it, your mother, assuming she is a full sibling to your aunt, has a fifty percent chance of also having it. Your grandmother or grandfather may also have it in this case. If your mother had it, you would have a fifty percent chance of having it too.

Now, if no other women or men in your family have had breast cancer, either you've gotten lucky as a family as no one else has developed the cancer yet, the mutation was new in her (if this is the case her kids could have it but no one else) or it came from her father.

There are other gene mutations that can cause it and these may be inherited in different ways. You can visit your GP if you're worried to see if you're eligible for genetic counselling. Hope this helps.