Chromosome 22

[mellymommy]

Hi there!

My soon-to-be-adopted son has an extra chromosome 22. The neurologist suspected Fetal Alcohol Syndrome but ordered the genetic testing to rule out or confirm any possible genetic disorders. Lo and behold, there IS a genetic disorder that is mimicing FAS.

So, we don't get into the geneticist until March 4th. Googling has done me no good, so I have no clue what type of chromosome 22 disorder we are looking at.

Can you give me any info on these types of disorders? What are the "treatments", does it get worse, what kind of expenses should we be prepared to dole out, should I be worried?

Thanks!

[askew]

What you are probably looking at is a duplication on chromosome 22 and not a real trisomy. I could be wrong, but I have never heard to T22. (T21 is Down syndrome)

This is a really good place to start:
http://www.rarechromo.org/html/home.asp

http://www.rarechromo.org/forum/DisordersLeaflets.asp
Scroll down to 22 and you can read about all the info they have collected on chromosome 22 disorders. It may not pertain to your son, but could give you a good idea as to the range of possibilities.

With chromosome disorders you won't really know for a while how it will effect him. There is often a big range, and some are mildly effected and some really severely and you have to wait to see where you child will fall in there.

Here is a thread from this forum about chromosome disorders too.

Good luck in the adoption process and congratulations on your new son!

[2boyzmama]

Congratulations on your son!!!!

My son has a deletion on Chromosome 22, but from what I have read, the symptoms can be similar whether it be a deletion, duplication, ring, etc.

Askew gave you some good links. What you need to find out (before the geneticist appt if you can) is exactly the mapping. My son, for example, is 22q11.2 deletion, meaning that he is missing a piece of his 22nd chromosome at location 11.2 Your son might be 22q11.2 duplication, meaning that he has duplicate of that genetic material at that location. The location matters because every piece of the chromosome controls different areas of the body. Children with 11.2 deletion, for example, very frequently have cardiac defects, but children with 22q13 deletion might not (I don't know, I'm just using that as an example).

You can also seek out others with that exact duplication if they exist, but first you have to know what the duplication is.

It may be hard at first to find people with the exact duplication, because as you found, there's a lot of misdiagnosis going on. I'm assuming that the test your son had done was a "microarray", which is a relatively new test (in the last 5 years) so before that, there wasn't a test available to find this kind of duplication. Therefore kids were being diagnosed FAS.

When my son had his microarray done, the geneticist warned us that the test might come back with an abnormality that they don't know how to interpret. She said that it's likely that a portion of the population is walking around with genetic defects without knowing it, and chalk it up to individual quirks. So it might be a few more years before enough of these tests are done and syndromes are named and prognoses are laid out.

So unfortunately no one can tell you what's in store. Even if your son has a recognizable syndrome (like my son, my son's is actually rather common), there's still so much variance in the presentation of the syndrome. My son has NO cardiac defects, for example, which is one of the hallmarks of his syndrome. No one can tell me why he has no cardiac involvement, but we thank our lucky stars about it! So that changes things a lot for him.

[mellymommy]

Thanks so much for that information! What a great place to start.

I also called our regular pediatrician, who has seen our little guy since he was born (he came to us at 7 weeks old), and he is going to do some digging for the exact report to get us some information so I know how to better research. I'm a bit of a research-aholic.

[2boyzmama]

http://www.chromodisorder.org/CDO/Ge...Disorders.aspx

Here's another webpage with good information about chromosome disorders, and they have a list of registered disorders. There are several involving duplication on chromosome 22.