Wednesday, November 16, 2011

Fragile X testing

The results of the Fragile X test were supposed to be in after 2 weeks, so I called to find out if they were back. They told me that the test they had done here at Duke was inconclusive, and they needed to send the sample out to the Mayo Clinic to do a different test. So it will be another 2 weeks before we get the results back.

The test they did here was the PCR. It looks for the normal copy number of repeats, which is around 30. (Fragile X is caused by having too many repeats in this region: around 30 would be normal, above 200 would be Fragile X) Since Sweets is a girl, and girls have two X chromosomes, they are looking for two bands on the PCR in the normal range. So they might see a 28 and a 30 on a normal girl. But on Sweets they only saw one band.

That doesn't necessarily mean she has Fragile X. She could just have the same number of copies on both chromosomes. If both of her chromosomes had 30 repeats, then they would just see one band at 30 - they can't separate the chromosomes. They can't tell from this test if they are seeing one chromosome's 30 or two chromosome's 30's. Two chromosomes with 30 repeats would still be normal.

If she has Fragile X, then it would only show one 30, so that is still a possibility. In that case, she might have one 30 and one 400, but the 400 is too big to show up on this test apparently. They can only see the repeats in the normal range. So, they have to do another test on her sample that can also see the big repeats, called a Southern Blot. The Southern Blot is a radioactive assay, and not a lot of places do them anymore, so that's why the sample had to be sent to Mayo for this test.

It's all the waiting that kills me really. It feels like this whole process is hurry-up-and-wait. Let's test her for this, wait months for the appointment, then wait again for the results, then when they are negative move on to the next thing and repeat. It makes the whole process take a very long time when we have to wait months between appointments. And the more specialized the docs, the longer we have to wait to see them. I remember when I thought the 3 month wait to see the neuro was a long time. Then I thought the 6 month wait to see genetics was a long time. Now it is going to be at least 8 months to see the developmental ped. It just keeps getting worse! I'm so sick of the waiting. I just want to know something!

Thursday, November 3, 2011

Genetics and audiology

Sweets had her long-awaited genetics appointment on Monday. They ended up wanting to wait for the results from the audiology re-test. If she did have a hearing loss, they would sequence her connexin-26 and screen her with an oto-chip for hearing genes. If not, they would make a different plan.

We already had our CDSA audiology scheduled for Wednesday, but they said they would like us to be seen by an ENT before they decided. They scheduled us for the Duke ENT, but the first available was not for 8 weeks, which was disappointing. I decided to call another local ENT to see about the wait there, and they said they could see us right away! I made an appointment for the next day, Tuesday.

We went to the ENT Tuesday and they took us in for the booth test. Whereas at CDSA we always did this test with speakers only, at the ENT they were able to do it with the headphones! They had Sweets sit on my lap while I bear hugged her to keep her arms down. She fussed when they put the headphones on her, but as soon as they started playing sounds in them she calmed right down! They were able to get the whole behavioral audiology done with the headphones, and they said they did NOT detect any hearing impairment! What a test!

We still went to the CDSA audiology appointment on Wednesday, where they tested her with the probes while she slept in her carseat. That worked out well too, and they also said that her hearing checked out with that test.

So, now it looks like hearing is NOT an issue.

So, what does that mean for genetics? Genetics said that they will not do the connexin test or the oto-chip. Instead, they want to test her for Fragile X. This is something that affects boys moreso than girls, because it is a gene on the X chromosome (and boys only have one, so when it doesn't work they are affected). Since girls have two X chromosomes, they can have a defect in one and still make enough protein with the other to be fine. However, some girls with the defect on one chromosome can show certain symptoms anyway. The severity ranges greatly and different girls display different subsets of symptoms to different degrees, some showing none at all. They said that they aren't saying that they think she has this, but many of her symptoms fit the ones on the list, so they would like to just be sure. Mostly they just want to rule it out.

One nice thing, is that they already have her DNA from when we had the microarray done, so she doesn't have to give blood again. They will just run the new test on the existing sample. It should take 2 weeks to get the results.

Other than that, genetics recommends that we see a developmental ped next. I called the one they recommended, and the wait is 8 months to get in with one doc, and 14 months to get in with the other! So I got on the 8 month waitlist. The 14 month waitlist doc is the one who specializes in Fragile X though, so I asked if I would have to wait that long if it turns out she does have that, and they said no, they have a Fragile X clinic on Fridays just for those kids, so the wait is not as long. Not that I think she has that, but it's good to know that we wouldn't have to wait 14 months to see a doc about it if she does!