Genetics 101

Last Friday, our geneticist from CCRM called. Apparently, our case is the talk of the clinic. Our geneticist had a meeting with the other CCRM geneticist, the molecular biologist, and the doctor to discuss our very unique situation.

At our first meeting with the genetic counselor back in April, because of the Robertsonian Translocation, she told us that the best chance is doing Pre-implantion Genetic Screening (PGS). There are three types of PGS. The first type of PGS is what's called Fluorescent In-Situ Hybridization (FISH). It tests only 9 pairs of chromosomes. The biopsy is done when the embryo is 3 days old, and it takes one day to get the results so a fresh embryo transfer is possible. The second type of PGS is what's called Comparative Genomic Hybridization (CGH). CGH tests all 23 pairs of chromosomes. The biopsy is done when the embryo is 5 days old. It takes 6 weeks to get the results, so the embryos would have to be frozen and then go back and do a FET cycle. The third type of PGS is called Microarray. Its technology is parallel to CGH and would have to do a FET cycle.

Back in April, the genetic counselor said that our option (because of the type of translocation) of PGS is to do the FISH testing (tests only 9 pairs of chromosomes). CGH wasn't even an option for us, even though it tests all 23 pairs of chromosomes, the technology wasn't that advanced yet to detect translocations.

So fast forward to last Friday when she called us. She said that we can now do CGH testing on the embryos whereas back in April our only option is to do FISH. She said that CGH can now test for translocations. That means that all 23 pairs of chromosomes, instead of just 9 pairs that we did back in July, can now be tested! Wow! She said that when Jerry's chromosomes are pairing up with my chromosomes and because Jerry has the translocation of the 13 and 15 chromosomes, the 13/15 pairing can sometimes disrupt the pairing in other chromosomes (even they're normal to begin with). So even though we know that there's a problem with 13/15, the resulting embryo might have more chromosome issues due to the balanced translocation pairing. Anyway, CGH technology has only been around for about one year now, and the success rate has been 80%. With the FISH testing, the success rate has been 50%.

The biopsy would be done on 5 day old embryos. There is a 1% risk of damage to the embryo. The CGH genetic test (as well as FISH) is about 90% accurate.

So if we choose to do the CGH testing on the embryos, it will test all of the embryo's chromosomes, not just the 9 pairs that were tested back in our July cycle. That might be one explanation that we weren't successful last July.

CCRM is one of the clinics that participates with a finance program called 'shared risk.' If we enroll in the 'shared risk' plan, we would pay a little bit more for IVF but that would only be a one time fee (about $10,000 more). But it would cover 3IVF cycles and 3 FET cycles. And by the end of that and we don't have a take home baby, we would be refunded 70% of the money. We would also get the 70% refund if at anytime we choose to stop doing IVFs or FETs. Sounds too good to be true, right? Well, here comes the kicker. We are only eligible for the 'shared risk' plan if we're not doing CGH. In other words, if we choose to do FISH we could sign up for the 'shared risk'. But if we choose to do CGH, we couldn't sign up for 'shared risk'. If not participating in the 'shared risk' plan, then we would have to pay for each IVF cycle.

Now comes the big decision. Do we go ahead and do CGH (with a 80% success rate) or stick with FISH (with a 50% success rate)? If we do CGH, it's all out-of-pocket for each cycle. If we do FISH, we could sign up for 'shared risk' and not worry about having to pay for subsequent cycles. What do we do?

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