Showing posts with label gene. Show all posts
Showing posts with label gene. Show all posts

Monday, May 5, 2008

All I Really Need To Know I Learned in 9th Grade Biology

SPOILER ALERT!!!! If you are related to me on my paternal side and/or you do NOT want to know the results of my genetics test, this post contains that information. I will warn you later on. It's at the end, so you can continue to read the rest of the post. I feel like I'm giving away the next episode of LOST or something, but I know that some people do not want to know about this stuff, and if they're related to me, I could inadvertently be giving them information they don't want to know. Okay...

Today I met with the genetic counselor who gave me the results of the BRCA (pronounced BRACK-ah) analysis. Before I go into the results, I want to explain exactly what this is all about. You may have heard about the BRCA gene mutation. Or maybe you haven't. It's a fairly recent scientific breakthrough where the mutation of 2 specific genes, BRCA-1 and BRCA-2, has been linked to certain cancers (most notably breast and ovarian cancer). When you have a problem with them, you say you "have the gene (or BRCA) mutation" as opposed to saying you "have the gene" (we all have the gene).

When functioning properly, these genes help prevent tumors and these genes are found in every cell of the body. We all have two copies of these genes - one copy from our mother and one copy from our father (the sperm bank, the milk man, etc). If you have the mutation, however, you now only have one functioning copy of the gene (or genes). That is, every cell in your body has at best one functioning copy. I guess if you were unlucky enough to have two parents with the mutation you could technically have zero functioning copies, but that would likely mean your parents came from Virginia and are cousins. That's why you shouldn't marry your cousin.

Anyway, due to certain factors (most likely environmental), the one working copy of your BRCA gene could also become damaged. These environmental factors could be things like smoking, drinking (oops), taking birth control pills (oops again), exposure to toxins, etc. It doesn't happen in all cells at the same time - it can happen in only some. Also, it depends on where it happens. If the one working copy of the BRCA gene fails in, say, a blood cell, nothing happens. But if it happens in a cell that makes up breast tissue, your body's genetic defense against breast cancer doesn't work.

It now seems obvious that having this gene mutation goes hand in hand with having a higher risk for developing breast and other cancers. I want to go over some statistics related to this in the
nifty pamphlet the genetic counselor gave me.

First is a chart showing the increased risk of getting cancer comparing the normal population vs. BRCA gene mutation carriers (numbers are percentages, and actually represent the worst case risk since there are ranges for the BRCA numbers)

Wow. Almost make me never want to drink again... almost.

The next chart shows how certain preventative measures can reduce the risk of getting cancer.

Most importantly, those who have the mutation or who are at risk of having the mutation will benefit from increased surveillance. This means getting mammograms early (preferably, earlier than the age that the youngest close relative was when she was diagnosed with cancer). For example, if your mother or sister had breast cancer at 35, you would want to be screened before age 35.

OKAY HERE'S THE PART WHERE YOU MAY WANT TO STOP READING!!!

Okay, still there? I figured that didn't work with the condom post, so I doubt anyone will stop reading now, either. ;-)

So, as I suspected I do have a genetic mutation of my BRCA-2 gene. Specifically, it's the germline mutation 2024del5 (whatever the hell that means), resulting in a premature truncation of the protein at amino acid position 599 (sure, whatever). I write that because I just wanted to clarify that the mutations are different - it's not a single mutation.

Any child I have would have a 50% chance of having the mutation. By default, my mother or father has it (given the family history, it's most definitely my father). And my sister has a 50% of having it.

Having this mutation means that I am much more likely to get cancer again, and the recommended treatment is probably going to be to have both of my breasts removed. I don't know if I really want to do that, so I'm going to do more research and think about it a lot more. I'm just letting you know now, please don't tell me that you think I should just "do it" (have a double mastectomy). I don't think it's that cut and dried.

Some people say that it doesn't matter if I don't have my boobs as long as I'm still alive. I know it's well-meaning, but I'll say right now that kind of offhand comment pisses me off (and if you HAVE said that to me, consider it your free pass :-). It's not vanity, it's identity. If you think it's an easy decision, you probably just think differently than me (and that's okay!). It's not that I don't value the opinion of my friends and family, in fact I really do. In the past few weeks, very many times I have heard something that just made me think differently and helped me form a well-thought out opinion. I don't want to discourage people from talking to me about it, I just want to make the statement that it's something I'm sensitive about.

And, finally, although this post may seem kind of gloomy, I wanted to give two more important pieces of information about the genetic testing lest you all call your doctors to get the genetic test (this is for you, Jules!). Only 5-10% of breast cancers are actually hereditary. Also, doctors don't recommend that everyone go out and get tested for the gene mutation. It's typically only ordered if you have 2 or more family members who have been diagnosed with breast or ovarian cancer before the age of 50.

One last bit of housekeeping... Are you still there? I realize that when I miss a few days you all get worried, but sometimes that just means I'm too well to blog! I'm working on a way to quickly update a daily status so that you know I'm doing okay. Stay tuned. Also, this week's chemo got moved up to Wednesday.