Can anyone tell me about genetic testing and down syndrome

[new_mommy25]

My SIL is pregnant. We are all very excited for her, especially me! Lately there has been a real damper put on this otherwise joyous occasion due to a gene that her boyfriend carries.

Here is what I know. Her boyfriend apparently carries a gene that can cause Down Syndrome. His mother actually had one pregnancy terminated when she found out her baby would have problems (not something I would do, but nonw of my business). After that she concieved Jordan and he was pronounced healthy. She never had anymore kids because she was too scared. Apparently the gene is passed on through his father and he actually has a cousin with downs. He is a carrier.

SIL voiced her concerns to the OB, but he blew it off. The triple screen was pronounced normal. However her boyfriends mom was freaking out because she was convinced that SIL needed more testing done. SIL just had her 20 week u/s done (it's a boy!) and finally got a doctor to listen to her concerns. Unlike the OB he said it was a BIG problem and that the triple screen might not pick up on it. So now Jordan has to go get genetic testing/counseling done and she will probably have to have an amnio after that.

We are all really worried about it. SIL should be enjoying herself right now but she is so down. She isn't doing any shopping or even looking at baby items because she doesn't want to be disappointed if something negative comes up.

Does anyone have any info to pass on or stories to tell? It would be greatly appreciated.

ps I want to add that I am sure my teminology is all wrong but I am not a doctor and know very little about all of this.

[JElaineB]

Here is a website with descriptions of different types of Down Syndrome. Read the information under "Can Down Syndrome be inherited?"

http://www.downsyn.com/whatisds.html

It sounds like your SIL's boyfriend is a carrier of the translocation form of Down Syndrome, which causes only 3-5% of cases of Down Syndrome. Plus it says if the father is the carrier the chances of him having a child with Down Syndrome might be as low as 1 in 20 to 1 in 50. Note that some forms though do give a 100% risk of haing a child with Down Syndrome. If your SIL wants genetic testing (amnio) done now would be the time to do it (if she would terminate in case of Down Syndrome, or just wants to know for sure), after she gets genetic counseling. I hope everything works out for her.

If you want anything from the website explained further, PM me and I'll do my best to help. I'm not an expert on Down Syndrome or genetic testing but I teach college biology so I can probably help you figure out or better explain any info you might encounter.

ETA more info about risks

Jennifer
mom to Jacob 9/27/02

[Rachels]

A wonderful, wonderful, wonderful book about having a child with Down Syndrome is Expecting Adam. It's one of my favorite books and is VERY reassuring about what it's like to mother a Down Syndrome.

-Rachel
Mom to Abigail Rose
5/18/02


"When you know better, you do better."
Maya Angelou

http://www.gynosaur.com/assets/ribbons/ribbon_sapphire_24m.gif Two years and counting!

[new_mommy25]

Thank you both for the advice. I'm going to show this thread to SIL.

[Bearhut]

From what I have been told, Downs is a from of Trisomy (where there are three instead of two of a certain chromosome). My third loss was a trisomy son (not the Downs chromosome). They should be able to tell from an amnio whether the child has a Trisomy Chromosome. As for the genetic testing, it couldn't hurt to have the tests done. In my case is was simply a blood test for both parties. This will tell them whether there is a genetic issue with either of the parents.

Hugs to you all.

[kelly ann]

A couple of weeks ago my OB told me about a newer test out called Translucent Ultrasound (I think that was the name). Anyway, I don't know all the details, but it detects extra skin folds around the neck which can indicate Down's Syndrome. She said with this and the triple screen, they can detect 90% of cases. Some women prefer this since an amnio carries some risks.

Sorry I don't have any further details, but maybe your SIL can ask her OB.

[new_mommy25]

Bearhut, yes that is right. He has an extra chromosone and can pass it on.

[JElaineB]

Angie,

If your SIL's BF is a carrier of translocation Down Syndrome and shows no symptoms of Down Syndrome he does not have an extra chromosome. All or part of this 21st chromosome is attached to another chromosome (it is "translocated" or moved to a different location). He has the right amount of DNA and thus no sympotoms. If he had an extra chromosome he would have Down Syndrome himself. The issue is if he passes on this extra portion to the fetus, along with his normal chromosome 21, and the fetus ends up with more than 2 full chromosome 21's. Most cases of Down Syndrome are caused by trisomys (an extra full chromosome), but not this inherited form your SIL's BF may be carrying.

Jennifer
mom to Jacob 9/27/02

[lfp2n]

I think that there is a short window when this test is possible, like 11-13 weeks.

HIH

Lucy

[chrissyhowie]

Angie,

Jennifer (JElaineB) gave you some great information to pass onto your SIL already. I just wanted to add that the genetic testing and counseling will probably answer much of the questions regarding SIL's boyfriend. Even with the history you described, unless he has had the testing done before, Jordan himself still may or may not be a carrier. Although he is at higher risk given the fact that there is a history of Down Syndrome in his immediate and extended family, still the vast majority of cases of Downs is spontaneous -- in other words due to chance. Genetic testing will be the only way to determine for sure. An amniocentesis will also provide confirmation about the baby and some peace of mind for your SIL as well. Even though I know they won't allay her fears completely, she should remember that both her triple screen and ultrasounds both came back with normal and reassuring results.

I'm so sorry that your SIL is going through this. I will keep her in my thoughts that all turns out well.