Sunday, March 28, 2010

Genetic testing

Huntington's chorea is a devastating condition involving GABA receptors leading to psychosis and lack of motor control developing in middle age, well past when the autosomal dominant gene could be passed on. There is no cure. Some people refer to it as "Woody Guthrie" disease. By the time it develops, patients will have passed this gene to half of their offspring. Researchers have found the faulty gene so now it is possible to tell the possibly affected offspring whether they have it. Was there a big rush for Huntington children to find out whether they had it? Aside from the ethics of having possibly affected children, it turns out that many preferred to wait and see if they had it. They still had the 50% chance that they didn't have it. They didn't want to lose that hope even though there was a large chance of relief.

BRAC1 and BRAC2 deletions are passed on in an autosomal dominant fashion also. If you have it, you received it from one of your parents and you have a 50% chance of passing it on to your children. If you have it, you are at increased risk for ovarian, breast and prostate cancers and possibly colon and pancreatic. So if you were to remove your ovaries and breasts, you'd cut your chances of having those deadly diseases significantly. At cancer support day at the Wellness Center yesterday, I ran into a woman whose BRAC gene has wreaked devastation in her life and in her family. She has 5 adult nieces who refuse to be tested even though their parent is nearing the end of Stage 4 cancer. Statistically half of those nieces have the gene too and could do something to lower their chances of having cancer but they don't want to know about it and now the aunt isn't allowed to nag them.

I haven't been tested for the BRAC deletions as my family history isn't consistent with having it. The main suspicion is that I had TNBC, the variety of BC that this deletion generally leads too.

The Red Cross finally told Dontae he has A+ blood so Naomi will need Rhogam in a few weeks given the high chance of incompatibility with the baby's blood. Only 3% of African-Americans are Rh negative so that was a long shot. The other day at the OB, the nurse was doing a history trying to identify any possible genetic redflags and asked Naomi if she were of Ashkenazi Jewish descent.
No.
Um, Naomi, your father is an Ashkenazi Jew.

We are hoping for hybrid vigor here. Naomi probably is not a carrier for the Sickle Cell trait either. Naomi and Dontae have a clear idea what their baby will be. If it is a girl, a supermodel. A boy, a basketball superstar. Don't tell them otherwise.

So I think I have moved on regarding these support groups. Cancer no longer is my biggest worry.

2 comments:

Teri B. said...

Oh, Sue, I can hear the wry tone that would have voiced that last comment about cancer not being your biggest worry. Looks like you might be too busy to worry...How is that puppy doing, by the way?

Sue in Italia/In the Land Of Cancer said...

The puppy dog is currently pouncing around my house on three legs while its owners watch TV. She fell and hurt her leg. She is putting more weight on it since the injury 2 days ago. It is not swollen or painful to the touch so I don't think it is broken. But if she doesn't start using it soon, to the vet. Do they have money for this?

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