Tuesday, December 11, 2012

Answers For Della

 And there it is...
The one gene of 22,000 that has made my baby the way she is. ASXL3. Such an unassuming name. A tiny change in the sequence of letters A, C, G, and T repeated 3.2 billion times. Such a simple and beautiful and complex structure that I believe can only be the work of God and not circumstance. Lots of mixed emotions today. But we have an overall feeling of gratitude. So thankful to finally have an answer because it is something denied to so many parents. We also feel gratitude that God has entrusted this special spirit to us. (Top photo by Lydia Tolman)

ASXL3 is one of between 20,000 and 25,000 genes and Della's ASXL3 gene has a mutation. Think of the human genome as a set of encyclopedias that contains all the genetic information that makes us unique human beings. All of that information is organized in a certain order, just like an encyclopedia is organized from A-Z. A specific gene is like an entry in the encyclopedia. Say the entry is all about dogs, it begins with dogs and ends with dogs. A mutation interrupts the order of a gene. So imagine reading the paragraph on dogs and half way through you come across a sentence about Mongolia. Suddenly, the rest of the paragraph has been changed. The theory is that the location of the interruption determines the severity of it's impact. If the second sentence of a paragraph is changed, the majority of the paragraph that follows it will be affected. If the last sentence is changed, hardly any of the paragraph is affected. Della's mutation is towards center of the gene, maybe 1/3 of the way down.

No one knows how Della's mutation happened. Chad and I also had all of our genes sequenced and we do not have the mutation. Della's mutation is classified as a de novo truncating mutation. That means the mutation spontaneously occurred, probably within a few hours of conception (TMI?). Many genetic conditions require that both parents carry the recessive gene that causes a disease. Remember Punnett Squares? Let's use hemophilia as an example. A person with hemophilia has to have both parts of the gene (hh). A person who doesn't carry the gene for hemophilia will be NN (for normal). A person who does carry the gene is Nh, but remember, both halves of the gene are required to have the disease, so Nh is a carrier but doesn't have hemophilia. Say NN and Nh got together and had a child, the child would either be NN or Nh but he wouldn't have hemophilia. Let's say the parents were Nh and Nh. The child could be NN, Nh, or hh.

We have been asked by TCH and Baylor to participate in research to study the ASXL3 gene. So far there have been two more little girls with a similar mutation to the same gene. One is in Germany and one is here in Houston! At the very SAME clinic! So if you happen to the the mom whose daughter has a ASXL3 mutation, PLEASE CONTACT ME! Hopefully this research will help other parents to understand what their children with this mutation need, like early intervention speech therapy, augmentative/alternative communication devices, physical therapy, etc. They can look to Della's life and know what to expect. I still hope that we can find someone who is 20 or 30 years older than Della and has the mutation. As honored as we are to be "pioneers," finding someone who has walked the path before us would be a great blessing.

Note: I wrote this back on August 6, 2012 which was the day we met with a large team of doctors at Texas Children's Hospital and got Della's genetic results back. It really has taken me all this time to process this information. Now when ASXL3 is searched, this post will come up (instead results solely made up of genetic testing done on rats). 


Marissa Palmer said...

Wow. So glad that you have some answers. I know that was very frustrating for you. I hope that you can find more answers, options, and hope with this diagnosis. And how awesome would that be to find the one person in Houston with the same diagnosis, someone who can truly understand your situation!

Karin said...

I saw this on fb, but couldn't comment until today. Wow. Answers for Della will most certainly mean answers for other children. Knowing is so ambiguous, especially when there is very little information that is helpful for you. I applaud your efforts in continuing to pursue answers. Della is beautiful. Belen is in the hospital right now. We are attempting to remove her shunt for good. These kids are amazing and difficult and amazing. :-) good luck on your journey to connect with more parents. :-)

Allison said...

Thank you for posting this. I appreciate you sharing the information with us. You're doing a great job being a mother to Della and Archer.