Sunday, August 4, 2013

A Five Minute Genetics Lesson

Jane wanted me to write this post so I could explain the details of our genetics appointment at CHOP yesterday.  So before I start let me say I don't claim to be a doctor, let alone a geneticist.  I don't know even a tiny fraction of what they know, and if we're being honest - they only know a tiny fraction about the amazing structures our Lord has created in the human bodies that carry us around in this world.  So here's as simple a description as I can come up with for a very complex subject:

Our physical bodies are made up of cells that do all the different things that keep our bodily systems running.  And at the heart of each cell are 23 pairs of chromosomes.  These chromosomes contain the genetic blueprint for our entire body in the form of DNA.  No two people have exactly the same blueprint, (except identical twins - but that's another story...)  We're each made unique with all the special characteristics that our creator intended us to have.  This blueprint also serves as an instruction manual that tells the cells how to do all the jobs they need to do.  Our DNA is divided up into pieces called genes.  If the DNA is the whole instruction book, then a gene is like a page of that book that has the instructions for one specific job.

Sometimes the information stored in a gene gets changed from its normal form - this is called a mutation.  When this happens, it's like that particular page of instructions was copied wrong and the cells don't know how to do that particular job correctly.  With around 25,000 genes in our DNA, people typically have many mutations in their genetic code - most of which have no significant effect on our lives.  Some genes though, are more important than others.  If these genes are coded wrong, it can result in diseases, disorders, or even death.  This is part of the reason we have two sets of chromosomes (one from our father and the other from our mother.)  If one set has a mutation in an important gene, chances are that the other set will not have a mutation on that same gene.  As long as one set of instructions is good, it lowers the risk of having problems with the way your body functions, or at least makes the problems less severe.

So what does all this have to do with Mercy, and why did we have her DNA tested?  It's very obvious from her appearance that she has albinism, but the fact is there are several different genetic mutations that can cause this condition, and some bring other medical issues with them.  Two of these which gave us the most concern are Hermansky Pudlak Syndrome, and Chediak Higashi Syndrome.  Hermansky Pudlak brings with it bleeding problems and lung disease, and Chediak Higashi brings severe infections and nerve damage.  Though these syndromes cannot be cured, knowing about them would help us be more prepared for the future - we would know what to look out for and get treatment quickly if any symptoms appeared.

Our prayers were of course that Mercy would not have any of these syndromes, and we are happy to say after the test results we received yesterday: she does not!  A blood sample from Mercy was sent to a specialized lab, where all of the genes associated with albinism and these related syndromes were analyzed from her DNA.  The only significant mutation they found was in the gene called TYR.  This gene carries the instructions how to make a chemical called tyrosinase, which is the first step in producing the pigment melanin, which gives our eyes, hair, and skin their color.  Both of Mercy's chromosomes have the same TYR mutation which short-circuits her body's ability to make any pigment whatsoever.

The great news is that the genes associated with both Hermansky Pudlak and Chediak Higashi syndromes did not show any of the mutations associated with those diseases!  So Mercy's diagnosis is what is called Albinism type OCA1A - which means her body cannot produce any pigment, but otherwise there are no other health concerns that we should expect from her albinism!

Combined with the news that her low iron levels have been rising nicely over the last few weeks, it was a great day for our family!  As one by one our medical concerns about Mercy are diffused, we are just left in awe of our great God who has walked side by side with us all along this journey so far, reminding us not to fear.  We agreed to place all our concerns at His feet, and He continues to amaze us with His faithfulness to Mercy.  Her amazing growth and development over the last couple of months is a living testimony of His power and grace, and we can't wait to see what He has planned next!

In the lobby waiting to be seen.

Ended the day at the Cheesecake Factory for dessert.


  1. God is good! Thanks for sharing! Rejoicing with you!

  2. "We agreed to place all our concerns at His feet, and He continues to amaze us with His faithfulness to Mercy. "


  3. Praising God with you that He has chosen to show His faithfulness, mercy and love to you in this way!

  4. Amazing News!!!! We are thrilled and in awe of God's goodness! Thanks!

  5. Praise God for the great news!!!! So thrilled to hear this today! We are FINALLY awaiting Travel approval and pray our girl who will be 3 in September will be as healthy as little Mercy! Will continue to pray for continued health and well being of Mercy! God Bless!

    Lisa, Ed, Brandon, Justin and hopefully sooner then later, little Leah :-)

    1. Lisa that is great news! The TA wait goes so fast, especially after a long LOA wait. Do you think you could travel over her birthday??? How special that would be. We left one week after getting TA. How will I be able to get updates from you? I would love to pray for you when you travel. Leah will be in your arms very soon. How exciting.