Good News
This is Ben. We have some good news to give about Joyanna’s testing, but more on that further down this post.
Two weeks ago
About two weeks ago we had an appointment for Joyanna with Dr. Herren, Philip’s epileptologist. We had wanted this meeting because Joyanna was showing some of the early signs of NCL and Dr. Herren had offered to see Joyanna and order tests. The test she decided to run was for the enzyme that is present or absent when someone has NCL. A normal person has a level of 80-320 of the enzyme; Philip’s test showed he had a level of 1 or less. The enzyme test only takes a couple of weeks to come back and would be a pretty good indication of whether Joyanna had NCL. If her body is producing the enzyme then she would be ok, but if the enzyme was not present in her blood, like with Philip, it would indicate she has NCL. Following the appointment, she had blood drawn and the test was sent off to the Mayo clinic to get tested and we settled in for a couple of weeks of waiting. During the last couple of weeks of waiting God has given us a good peace about whatever the outcome of the testing.
Yesterday
We had an appointment with Philip’s genetic doctor. Rather than schedule separate appointments for Joyanna and Ethan, he just combined all of them into one appointment. We talked with a genetic counselor during the appointment and she basically went over a lot of the scientific basics of how Philip got NCL from us. Basically Becca and I both carry a working and non-working gene (TPP1). Philip inherited the non-working gene from both of us and thus his body does not produce a specific enzyme which is necessary to keep his neurons healthy. Because that enzyme cannot be produced and is not present in his body, the neurons are slowly being destroyed by the disease. There is basically no treatment to replace that enzyme or get the body to start producing it, though the medical field is studying the possibilities.
There would be a 25% chance that Joyanna or Ethan also inherited both non-working copies, a 25% chance that they would have inherited our working copies of the gene, and a 50% chance that they would have inherited at least one working copy of the gene and one non-working copy of the gene. The latter would mean that even though they are carriers of one non-working gene, the working gene would produce the enzyme and they would not be affected.
We talked through some of the ethical considerations regarding whether to have Joyanna and Ethan tested for NCL. Most of the discussion was about things that Becca and I had already discussed over the past few weeks, and we had already made the decision to have both Joyanna and Ethan tested. After talking for a while, the geneticist was confident that we had “thought through” the ramifications of knowing whether or not Joyanna and Ethan have it. He agreed to test both of them, and we had labs drawn for both of them following the appointment. They will send off the labs to get tested. We had thought it would take several months to get the results of the genetic testing back, but the geneticist said that since they are specifically testing for deviations in a specific gene, the testing would only take a few weeks.
For Joyanna: Since we had already sent off the enzyme test for Joyanna, the geneticist said that we would get the enzyme test back and it would be a pretty conclusive answer, but that the genetic test would just be a second confirmation of the enzyme testing results.
For Ethan: If the genetic test came back showing that Ethan has NCL they will do an enzyme test as a second confirmation. If the genetic test comes back showing that he does not have NCL, no further testing will be required.
Here are a couple of answers to questions we had, and you may have:
Because this specific gene causes late-infantile NCL, it is virtually impossible that Becca or I would have other versions of NCL such as the “adult-onset” type. Becca and I do not have to be concerned for ourselves for this particular disease. If we had had it, it would have shown up when we were kids.
While it is likely that some of our siblings carry at least one recessive gene for late infantile NCL like we do, there would not be concerns for them unless they happened to have married someone who also carries the recessive gene for late infantile NCL. The chances are very low, but it does happen—as we have seen with Becca and me. The genetics counselor yesterday said that they estimate that everyone carries at least 8 recessive genes and potential for genetic issues could develop, but very few people are affected because it is very unlikely they will marry someone who has the exact same recessive gene they have.
Today
I got a call from Dr. Herren this morning about Joyanna’s enzyme test that was done 2 weeks ago. It indicated that her level of the enzyme is 22. While this is below the normal level of this enzyme, it indicates that at least her body is producing some of the enzyme. Basically she is a carrier of one recessive, non-working gene, like Becca and I are, but she also has a working copy of the gene which is producing the enzyme.
This is a pretty conclusive indication that she does not have NCL. However, because of the chance of a false result and because there is enough about genetics that they still don’t understand, Dr. Herren was going to suggest getting the genetic test done to confirm the enzyme testing results. As you already read, we sent off that test yesterday.
So at this point we are thanking God that, it appears, He has seen fit to spare Joyanna from NCL and still praying that the results of the genetic tests will confirm what the enzyme test revealed. Whether Joyanna had NCL and God saw fit to change things over the past few weeks as a result of your prayers, or whether she never had it to begin with, we will perhaps never know till we get to Heaven, but it is a huge blessing all the same. Currently we are praying and trusting that God will give the grace for the outcome of Ethan’s testing.
Thanks for your prayers and encouragement!
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Philip & Joyanna's Story
December 17, 2009 -
August 25, 2018 Philip's memorial slideshow and funeral service can be viewed by clicking on the "Philip" tab at the top of this page. You can read more about Joyanna's story by clicking on the "Joyanna" tab at the top of this page.
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