Genetics Appointment

Just prior to discharge from the NICU, Elias had another blood sample sent to a lab to test for the most common FA gene mutation of the 13 known, FANC-A. This test took about 6 weeks to complete, and would help to decode where in his genetic make-up the mutation occurs. We could use that information to pinpoint where to look for the same information in our family, but much quicker. It is like reading a book, finding the single error, and recording the page number, because anyone else's copy would have the error in the same place. So you can simply turn to that specific page and find the same error, without the need to read the entire book. At our appointment yesterday with the geneticist, we learned that the FANC-A test returned with negative result. This does not  mean that his diagnosis is incorrect, it means he has another one of the remaining 12 mutations; FANC-B, FANC-C, FANC-D1 (BRCA2), FANC-D2, FANC-E, FANC-F, FANC-G, FANC-I, FANC-J, FANC-L, FANC-M, or FANC-N.

The negative result for FANC-A leads us to do a complementation analysis. This analysis allows them to methodically process step by step from the most common to the least common. The analysis is complete as soon as the mutated gene is found. However, only 9 of the remaining 12 currently have testing available. FANC-I, FANC-M & FANC-J complementation tests are still under development. The tests could take as long as 8 months if they progress to the later complementations, but hopefully it will be around 10-14 weeks. Why is finding this information so crucial? Speaking strictly on a personal level, to aid in research data first off. We feel the more information the researching doctors have on as many known patients as possible, the quicker they will find a way to cure this horrible disease. Even more important than that, is the impact the results have on our families as a whole. Not only for the current generations that are at child bearing age, but future generations as our families continue. We feel it is important to isolate this and find out where it exists within the family so we can identify those at risk of having an affected child. We are not likely the only carriers in the family, but none of us even imagined this until Elias came along. 

While FA is primarily an Autosomal recessive inherited gene there is also X-linked recessive, which is the other potential for Elias. Defining and isolating the difference again is crucial to identifying who in our families are at risk. The major difference between the two types of recessive genes we are focusing on is which side of the family does this affect and what the risk rate will be for future children. We will focus on the least likely, but not impossible, scenario first, the X-linked recessive gene. This is where only the mother (Katharine) carries one copy of a gene mutation for FA. In this case only a son can actually inherit that mutation. This means that any boy conceived would have a 50% chance of inheriting, and being diagnosed with, FA. Males can not, however, become carriers, only females. Likewise, females in this x-linked recessive scenario can not be affected with FA. But girls would have a 50% chance of being a carrier themselves. This now puts the daughter's future sons at risk. Keep in mind that these 50% odds do not mean if there are two girls and one is a carrier that the other is not. It is possible for two sisters to both be carriers because they each have their own 50/50 chance of inheriting the mutated gene.

Now let's shift gears to the more likely scenario. Katharine and I each carry one copy of a gene mutation for FA. With this scenario there is a 25% chance that any child we have will have FA ( as Elias does), a 25% chance they will be completely unaffected and a 50% chance they will be carriers of the FA gene, which again puts their children at risk. Each child we have will have the same chance to be affected, a carrier, or unaffected. This can affect both sons and daughters, unlike the last scenario. Since this is the more likely situation, we have a more difficult time and larger sample to draw from and isolate to determine who else is at risk.

That is what we learned at our appointment on Thursday. The tests are unfortunately very expensive, but what do you do? You find a way! Some potentially will be covered by insurance and that is being researched by our genetics counselor to determine our options for funding these tests. One of the labs that do this testing is at Cincinnati Children's Hospital. We are reading over some information we were given about this and other potential options. We also discussed participation in research programs, which is of tremendous interest to us. We will keep you posted on how this goes, as always. Please let us know if you have any questions.