Genetic Testing

Posted to Facebook March 20, 2012

Met with the geneticists today to draw our blood and get the testing started. In 2-4 months (after our entire exomes are sequenced) we will either know what took Drew's life or have the knowledge that medical science has not progressed far enough to find the answer.

Posted to Facebook September 6, 2012

After more than a year of wondering, questioning, praying, hoping and doubting we finally will meet with the genetics team tomorrow morning to hopefully get the answers we need regarding Drew. Will post more tomorrow...

Posted to Facebook September 7, 2012

As Brittany and I began the genetic testing process to find what disorder took Drew from us we faced a choice between two alternative testing paths. We had no way of knowing what the future outcomes of either path would be or which path was better. We considered carefully and prayed heavily knowing that only by selecting the proper path would we ever have a chance of finding the answers we sought.

We both felt strong confirmations regarding our choice even though it was (by far) the more expensive and complicated of the two.

Today we were told by the genetic counselors that if we had chosen the other testing path, the answers would have never been found and Drew's death would have remained a mystery. While the path we chose hasn't revealed all of the answers (not yet at least), it has provided such clear direction that a few further tests have a strong possibility of telling us why Drew died.

We are thankful that God answers prayers...

Posted to Facebook September 13, 2012

Brittany and I received some significant results last week from the genetic testing we began earlier this year. The basic premise of this testing was:

1. To determine which form of Non-classical Homocystinuria with a Cobalamin deficiency affected Drew (there are several known subtypes, each with a different prognosis and treatment); and
2. If the answer to the previous question was obtained, then we would be able to test future children before the disorder affected them to the degree it did Drew.

While it’s not technically true that Brittany, Alexis and I had our entire genomes sequenced (there were some slight technical differences), the genetic testing examined every aspect of each of our genetic codes (over 99%). The results were as follows:

• I am a carrier for sub-type F of the disorder. The testing found that this was not something that I developed, but rather something that has been passed through our family’s genes since before our ancestors emigrated to America. It does not affect me because I only carry one copy of the gene. Thus my other copy of the same gene (the normal copy) masks its effects and I am normal (at least with respect to the disorder, haha).
• Brittany is a carrier for sub-type G of the disorder. Again, the testing found that this was not new to Brittany, but rather had been passed down through her family’s lineage for several generations. She is not affected for the same reasons (her normal copy of the gene masks the effects of the altered copy).
• Brittany and I are not in any way related. We share no common ancestors at all (except maybe Adam and Eve, haha). Sounds obvious, but it was one possibility…
• Alexis does not have, nor will she ever develop, any form of this disorder. This is great news to us because several forms of the disorder don’t begin affecting people until they’re adults. Needless to say, we were worried. But Alexis will never be affected.

While all of these results are fantastic (we were originally told not to expect anything because of the complexity of this testing) the results are also puzzling. This is because all of the research has shown that this disorder is an Autosomal Recessive disorder, which means that the only way for a person to be affected is to inherit two copies of the exact same altered gene (one from each parent). With Brittany and I being carriers for different types of the disorder (each affecting different genes) neither type F or type G should have affected Drew (although he could have been a carrier for neither, one or both). This leads to two possibilities to explain what happened to Drew:

1. It’s possible that the current understanding of the inheritance pattern of this disorder (Autosomal Recessive) is incorrect. If this is the case, it would be a HUGE breakthrough in the understanding of this disorder and would ultimately lead to earlier and better diagnosis (which means fewer people suffer and/or die as a result). If this is the case, it would have been discovered because of Drew.
2. It’s possible that Drew inherited Brittany’s altered copy of the gene in question (passed down through her family line) and at the exact same moment he experienced (on his own) the exact same alteration on the exact same gene. The same could also have happened with my altered copy. The chance of such a thing happening is extremely rare. In fact, it’s so rare that it’s never been seen before.

While either possibility seems very unlikely, the actual results of the testing were so clear that it became possible to run a very (very, very) targeted genetic test on the one piece of DNA we have remaining from Drew…his dried blood spot that was taken at his birth by the New York State Newborn Screening Lab. The amount of DNA on this blood spot is extremely small so the only way it could be tested was to find exactly what needed to be looked for. The results of the genetic testing on Brittany, Alexis and I were specific enough to make this possible.

As if all of this wasn’t miraculous enough (and I don’t say ‘miraculous’ lightly), the results of the testing were so significant that the company who did the tests has asked our permission to use the results to write a ground-breaking research paper to be published in all the medical journals. You see, this form of testing is very new and we were among the first to run it. Usually to test for a genetic disorder, you have to test the affected person. But with this new method, the family members were tested to narrow down the field of interest and then the affected person’s DNA was tested. It’s groundbreaking.

Furthermore, because our results are now part of the company’s Research program they’ve agreed to pay for all future testing and will also speed up the testing significantly.

We are grateful for everyone’s support and prayers. We are grateful to be Drew’s parents. We are grateful for the blessings of the Lord…