I am hoping I can add something useful to Squishy's excellent post. I am attempting my first IVF cycle and if all goes to plan will do PGD. With SydIVF I had a choice of a 5 aneuploidy test or 7 test. I was told by the PGD scientist that the 7 test is more likely to have an "unknown" outcome because they have to clean the slide to reperform the extra two tests. But if they are looking for something specific, for which I think might use PCR in your case (also has a higher accuracy), they will only need to do one test. Hope this makes sense and is of help to you.

I really recommend ringing Syd IVF. When I originally rang I was put through to a PGD nurse and she was incredibly helpful and prepared to answer a barrage of questions from me.

Good luck
WTH