So a few weeks ago, Evan, Connor and I got our blood drawn to test for these mutations.
From my understanding (which is minimal at best - my lowest score on my ACT by far was the science section), everyone receives genes from both parents to make up their entire genetic coding. These genes are like a set of instructions in making the different proteins in our body.
In Brenna's case, her body began forming, and when it came to the ABCA12 gene, it simply stopped because of the "errors" in the instructions. The ABCA12 gene is responsible for forming the ABCA12 protein that is essential in developing the outer layer of skin (the epidermis). So Brenna's skin lacks this obviously important protein.
Brenna's two mutations are S1249X and R714X. Basically there should be a S and R where the Xs are. Our results showed that I have the S1249X mutation, and Evan has the R714X mutation.
Because we both have one unaffected gene, it acts as a backup and our bodies still produce enough of the protein so that the mutation doesn't affect our skin.
And we learned that Connor is also a carrier; he has my mutation, S1249X. I am two for two in passing along my bad gene vs. my good one. Of course, the chances of him marrying someone with this mutation are incredibly tiny, which is very comforting at least.
So every child of ours has a one in four chance of having Harlequin Ichthyosis. (remember high school biology?!)
- 25% two unaffected genes
- 25% unaffected gene from me, mutation from Evan
- 25% mutation from me, unaffected gene from Evan (like Connor)
- 25% two mutations, resulting in Harlequin
I had really hoped that Connor was unaffected, but we are feeling a little relief now, knowing these definite results. It's a lot to wrap my head around, and I was happy to have the chance to meet with our genetic counselor today to get a clearer understanding. In a sense, it provides a little closure for us about Brenna's condition and why her skin is the way it is...
I loved this section in biology - where we would make those little charts about eye color and hair color. I think it is great they can do testing like this and now it totally makes sense for Connor's wife to have genetic testing as well. Then again, I'm not sure what I would do with information like that! What a tough situation to be in, knowing your child COULD have a mutation like this due to your own genes.
ReplyDeleteI have just been diagnosed with a blood virus from a transfusion I received before blood screening for this particular virus was done, and was informed that it can be transferred perinatally, although the chances are very slim. I had no idea I was sick when I carried my children - I felt fine and they were healthy at birth. Needless to say, I have been through every emotion I could experience (I hope!) over this, and it all came down to what a friend reminded me of the other day - "It's in God's hands now." You guys are doing just a wonderful job. Just love each other EVERY day and it will all work out for the best - it ALWAYS does.
ReplyDeleteEthan's disease is the same way. Jeff and I are both healthy carriers and it takes two mutations for a child to be born with a Peroxisomal Biogenesis Disorder - Zellweger Spectrum. We had no idea we were carriers either.
ReplyDeleteWhile there is no way to make sure to check carrier status for everything, and some diseases "just occur" we know encourage anyone who is considering starting a family to do the carrier testing by Counsyl - www.counsyl.com prior to getting pregnant. It screens for carrier status for more than 100 different diseases. It can't catch everything but it can catch a lot.
Will u have more kids now knowing this ?
ReplyDeleteI know it's alot to take in. I have a child with genetic disabilities too. Kno that you have lots of options for having more kids. I have healthy children thanks to the magic of high tech in vitro called pre-implementation genetic diagnosis (PGD). Good luck with everything! You have a great attitude and that is 99 percent of what matters ;)
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