aCGH accuracy

Rate this Entry
Quote Originally Posted by nuthinbutpink View Post
I and I am sure a lot of you have been thinking about the accuracy of the testing in light of CT's outcome. I have been doing some reading and I have no answers yet but I want to share bits that I am finding in cyber space- so you know what googling can do and please do your own research and form your own opinion.

Michaela, one of my google searches landed on a post you made on Saleh's board- this is what he said in 2010 about mCGH when you asked why it CANNOT be used for GS-

Because mCGH technology determines normality of DNA. There is too little difference between X and Y and the accuracy suffers when you are also analyzing 22 other Xmes. A very recent enhancement in CGH technology, known as Array- CGH or aCGH. This will have several distinct advantages over the “conventional CGH”. First; Array CGH can be done more rapidly,; Second, it has the ability to identify the gender of the embryo; third, it will provide an ability to recognize additional chromosomal and genetic defects (that conventional CGH can not do); and fourth; it will allow identification of additional chromosomal/genetic abnormalities, thereby preventing them from affecting the baby, through selective embryo transfer. The drawback with Array CGH hitherto, is that it has lacked sensitivity and specificity and thus it has not been possible to perform reliably on single cells, being that the amount of DNA available is too small. There has also been too much “background noise”. We have been addressing this issue and believe that we will solve this problem making it possible to replace conventional CGH with single cell Array CGH. We hope to be able to supplant conventional metaphase CGH with Array CGH in a few years. Given the fact that we have now proven the efficacy of Staggered IVF and egg freezing based upon data obtained through “conventional CGH” coupled with a growing demand we are uniquely positioned to convert from “conventional CGH” to Array CGH, cost effectively. These are thrilling but at the same time, challenging times!

So, my question is how good is aCGH with ONE CELL FROM DAY 3 now? It seems that with CGH, they need to replicate the DNA over and over again and can "run out of material" and the X and Y sex chromosomes are the smallest of all chromosomes and sometimes don't show male or female if I am reading all this right.

Does ANYONE know if CGH- in any form - has 99% accuracy for GS? Not 95, 94 but 99% thuse HUMAN ERROR being the only cause of the incorrect gender?

I haven't looked into GSN yet so I have no idea if the way they test would also mean human error is the only way.

I know with FISH it is. Human error is the only way it gets screwed up- either one X and one Y light up with the dye or not. Anything less than 100% with that is abnormal.