PGD/IVF - can someone help me?

[Aimz]

I may need to go down the road of PGD and IVF due to an inherited genetic disorder (muscular distrophy) of which I may be a carrier. I'm looking at my options and I'm hoping someone can explain what these various terms mean. There are a few different types of cycles when going through PGD and each one has a different cost. I'm not sure which one I would need to go through to either determine gender or determine if the embryo carries the defective gene.

Polymerase chain reaction (PCR) cycle
Translocation cycle
Aneuploidy Screening cycle

There are explanations on the Sydney IVF website but I really need it in layman's terms!

Also, what is the difference between IVF and ICSI? What do they mean?

Any help would be appreciated .

[butterfly_warrior]

I can't help much with the PGD stuff...

But I can tell you the difference between IVF and ICSI.

With IVF they basically put the eggs and sperm together and let them do their thing, only outside the body.

With ICSI, they hand pick each sperm and inject it into each egg. They use this in the case of sperm problems, so if all is ok on that side of things then you probably won't need to use ICSI.

I hope someone else can give you the information you need... and even more - I hope that your genetic tests come back clear and you have no need to use IVF and PGD at all.

BW

[Aimz]

Thanks for the explanation BW - I knew it was something along those lines I just wasn't 100% sure.

I'm hoping everything comes back clear as well so I can get off this scary ride! It doesn't hurt to prepare though and DH and I are both research nuts so at least this info is providing some degree of peace of mind.

Anyone else know about the PGD stuff?

[briggsy's girl]

Amy, i'm not sure exactly how PGD works (as in the processes) - but i would think PCR would be a requirement (it is the process by which they amplify the number of copies of the gene they're looking for). they only take one cell to test, so they need to amplify the information HEAPS to have enough to run through the tests

Trying to drag up my genetics study from years ago, translocation is where a section of DNA moves from where it SHOULD be, to another location on the DNA strand, and changes the structure and action of a whole section of DNA. i can't recall exactly what Aneuploidy is, but i think it's to do with having a section of DNA repeat when it shouldn't, changing the characteristics of that segment (i'm running on really fuzzy memories from study at uni!) - i may be wrong here, but it's vaguely familiar

essentially, i'd think that, depending on the type of genetic anomaly that leads to the muscular dystrophy, they'd run PCR and then one or the other of those two other cycles to locate the "dodgy" gene. Melbel has gone through IVF/PGD - hopefully she'll find this thread and pop in with a better answer...

hope it's all a theoretical issue for you anyway

BG

[*Squishy*]

Hi,

You said that you may be a carrier of a muscular dystrophy. Do you know what type? (ie - duchenne, myotonic etc). Has genetic testing been done to identify the gene error (mutation) in the affected person in your family? Because if it has, then it may be simple for you to have the blood test done to find out if you are actually a carrier. If you haven't been to see a genetic counsellor to talk about these issues, I would recommend you do so!

Polymerase chain reaction (PCR)

This is a test that is used to look for errors or mutations within a single gene. This is most likely the test you would need to look for the gene mutation associated with whichever muscular dystrophy is in your family.

Translocation

A translocation is where 2 or more chromosomes in a person's cells have rearranged. This can involve either the chromosomes joining together or swapping pieces. Not usually a problem if the correct amount of genetic material is still present, however a person who has a translocation has an increased chance of having pregnancies with an abnormal amount of genetic material which can cause problems. This technique would not apply to you.

Aneuploidy Screening

Aneuploidy is where there is an incorrect number of chromosomes in the cells. This could be too many chromosomes or too few. An example of this is Down syndrome where there is an extra chromosome number 21. Aneuploidy screening can tell you the gender of the embryo. Anyone going through IVF can use PGD for aneuploidy screening so this is something you may also consider having done. Hopefully someone who knows more about IVF/PGD will be able to comment on whether multiple testing of embryos significantly impacts on their survival rate.

I hope that this is useful. Everyone - please feel free to correct me if any of this information is wrong!

Good luck, I hope that it all works out for you.

[Where there's hope]

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

[Sara69]

Hi,

I am going to start PGD with SIVF in November due to a similar disorder, fell free to message me privately if you'd like to know more (I hope that's possible I have only recently joined BB).

I think you should urgently get some genetic counselling as this process can be very distressing. About the different options Prof Morgan at Sydney IVF is very good at explaining these.

Depending on which muscular dystrophy you are talking about some good resources may be here University of Washington - Department of Neurology - Division of Neurogenetics

Sara

[Kmn]

ICSI (where the sperm is injected into the egg) is a required part of IVF with PGD for genetic conditions - it means that the genetic tests don't get mucked up by any other sperm DNA that may be lurking around.

PCR is a process where DNA is reproduced - it's the "photocopier" that takes a single cell's DNA and turns it into enough DNA to test.

[Aimz]

Thanks for the explanations girls - I'm pretty sure I get it now.

BG - Thanks for the info!

*squishy* - I will be getting tested at the end of this month to find out if I am a carrier. I am asking these questions for the purposes of gaining information to prepare for the worst. I do know what type of dystrophy - it is called Scapuloperoneal Dystrophy which is a very rare form and there isn't much information about it. They have been able to identify where the defect lies on the gene so testing is available. Should it come back that I am a carrier then the next step will be to see a genetic counsellor. Thanks for all the info.

where there's hope - I was actually wondering about this. So I can either choose gender (only males can be affected by this defected gene so we would choose to have a girl) or I can have the embryo's scanned for the defect irrespective of sex - but not both because it can cause too much damage to the embryo? Am I on the right track? Can I ring Sydney IVF without a referral from my GP?

red lady - thanks for the link - I will check it out today. If the test comes back positive we will be seeing a genetic counsellor asap as I will need some help getting through this. Thanks for your advice.

KMN - Thanks for the info!

[Kmn]

My info is a year old and this field moves quickly, so do check to see if things have changed.
But - if they are only able to take 1 cell from the embryo to test, then they can only do 1 sort of test (either a PCR-based one or a chromosome counting one). So you can either get tested for cell-division-problems (which is something that Sydney IVF does as part of a service for women with issues with recurrent miscarriages) or you can get tested for one or more specific defective genes.

What may have changed is that they may be able to culture the embryos through another cell division and hence have enough cells to take more to test.

[briggsy's girl]

Amy, i would suggest you make a call to SIVF and just ask - say you're potentially going to have to go through PGD and would like to be able to speak to someone about it all - the counsellors associated with the IvF clinics are usually really clued up on the process, and you might be able to get an appointment with one...

[HotI]

So I can either choose gender (only males can be affected by this defected gene so we would choose to have a girl) or I can have the embryo's scanned for the defect irrespective of sex - but not both because it can cause too much damage to the embryo? Am I on the right track?

Hi Amy

With PGD, they combine the egg and sperm and then grow the 'baby' to the 8 cell stage. They remove one cell and then test it genetically.

Because they only have one cell to test with, they can't do all the genetic tests that they can do on adults (where they get lots of cells from a small blood sample). And they can usually only do one test, because all the DNA from that one cell gets used up in the test.

It is not always possible to look for a specific mutation. It depends on whether the mutation is a small one (e.g. one 'letter' in the gene is the wrong letter) or a big one (e.g. a large section of the gene is deleted). A mutation that effects a large area of the gene is sometimes harder, or impossible to do with PGD.

The genetics clinic or IVF/PGD will be able to help you when they know the gene involved, and the family mutation.

If it is possible to test for the family mutation with PGD, the scientists will first have to devise a specific test for the family mutation. This will take a bit longer than when they are testing for something that they do regularly (ie gender or extra chromosomes). They will devise the test before you start egg collection etc to make sure that it works and will be ready for when its needed. This testing phase will also cost extra on top of the IVF/PGD stuff.

take care,

kate

[Aimz]

Hi Kate, thanks for explaining it to me.

So to avoid having to devise a specific test, we could just ask for gender determination - is that right?

Only males can be affected by this specific illness so if we chose to have a girl she would only be at risk of being a carrier.

[Where there's hope]

AmySarah - To get started I just rang Sydney IVF straight up without an appointment. I told the receptionist why I was phoning and she tracked down a PGD nurse straight away. They really were very helpful. If you choose to go with them (I can only speak of my experience), it includes an interview with a PGD nurse and a PGD scientist who will explain the process. But you will need your GP to refer you to an FS first. My FS happened to be with SydneyIVF so it all sort of fit in together IYKWIM.

Also, at Sydney IVF they do the PGD at Day 5 Blastocast stage (where by memory there are 70 to 100 cells). The cells they remove are not a part of what will be the actual baby. They told me they remove a few cells, not just one. But if you do PGD at a clinic where they do it on Day 3 (when there are approximately 8 cells, by memory) they can only test one cell.

[Aimz]

Thanks so much where there's hope.

Should I ring soon or should I just wait until I find out if I'm a carrier? Will they just tell me to wait until I have my test before giving me any info?

[Where there's hope]

If you are already having testing done, I would wait until you know what your situation is. Then you can be armed with more direct questions when you ring the clinic.
Good luck

[Kmn]

Hi Kate, thanks for explaining it to me.

So to avoid having to devise a specific test, we could just ask for gender determination - is that right?

Only males can be affected by this specific illness so if we chose to have a girl she would only be at risk of being a carrier.

That's right - gender determination would be quicker/cheaper/easier for the clinic than gene hunting.

[Aimz]

Ok I'm pretty sure I understand now! Thanks so much for your help girls.

Now just to wait until the 22nd when I can get tested...