Monday, June 13, 2011

Is It Genetic?

Mason had his 9-months genetics consult recently. He is still a puzzle to the team but he has features of the following genetic conditions so they are interested in watching him for other signs of any of these as he grows to determine if he will need testing.

*Rubenstein-Taybi Syndrome (if Mason has this syndrome, it's probably not caused by mutations in the usual RSTS genes, but instead, is a new variant of the syndrome caused by the deletion he and I share--one of the  genes we are missing interrupts signaling pathways for both RSTS genes. They do not know at this point if the deletion is the main problem, but because of his brain malformation, colobomas, broad thumbs/toes, thick, dark, curly head of hair, feeding issues and narrow nasal passage etc they think this possibility is "intriguing." (Ironically ,before we ever got the results of his karyotype and microarray at a few weeks old in the NICU, we asked the docs if he could have this syndrome; they assured us "definitely not." Now it seems high on the list of possibilities. We have found so many friends online whose little ones have the classic versions of this syndrome and have been very encouraged with the progress we are seeing in them, and have found much so much in common with Mason. In this case, if this is the problem, then it is definitely genetic and we have up to 50% chance of passing it on to another child (for that matter, Micah could have the deletion too, but he and I may have a mosaic version of it --not in as many cells as it is in for Mason (the only way to test for that would be an invasive procedure and they won't do it without another reason for a surgery).
*Mosaic Trisomy 13 (Mason will probably get a test for this when he is about a year old when he is sedated for other procedures to be sure this is not a hidden genetic issue in the family. Trisomy 13 and Rubenstein-Taybi can mimic each other clinically and our family has some physical signs of genetic issues like mosaicism or possibly a translocation even in otherwise healthy individuals - for instance, me, Micah, Mason, Dad, etc. all have persistent epicanthal folds around our eyes (you can see if you have them by gently pulling downward on top of
epicanthal folds EDS
 your nose on either side) - but according to National Institutes of Health, "A child who is not Asian and is born with epicanthal folds may be examined for additional signs of Down syndrome or other genetic disorders."  If you or your kids have these somewhat obviously and you are not of Asian descent, it wouldn't be a bad idea to get genetic testing in my opinion, even if you are "basically healthy." (It can be an innocent trait or not, like so many other genetic issues--if you have it in combo with other genetic type health problems it's more likely to be significant in some way - I was also born with eye trouble/strabismus and my head is very small, etc - still not sure if it matters or not).

Prominent epicanthal folds are common in Rubenstein-Taybi, Trisomy 13 and various genetic conditions including Ehlers-Danlos Syndrome (a similar hypermobility issue to EDS also runs in our family - there are some wacky things my mom, Micah and I can do with our joints/skin/connective tissue, etc....
hypermobility Ehlers Danlos Syndrome EDS
hypermobile hands/fingers/thumb

hypermobility Ehlers Danlos Syndrome EDS
hypermobile thumb Ehlers Danlos Syndrome EDS
hypermobile wrist/thumb

hypermobile tongue/Gorlin's sign Ehlers Danlos Syndrome EDS
"Gorlin's Sign"
hyperextensible stretchy skin hypermobility Ehlers Danlos Syndrome EDS
missing frenum Ehlers Danlos Syndrome EDS
missing frenum is specific sign of EDS - Mason's is either missing or malformed, dr isn't sure

Regardless, I strongly feel that something is going on that is both subtle and hereditary in our family, especially if the deletion is not the main issue, and if so, it is not necessarily "a remote chance of recurrance" as we were first told by the docs, and in fact could be highly likely to recur (with mosaicism the mom/carrier could be practically asymptomatic but the baby could be affected fully or to varying degrees). I'd be relieved to know if it was just a one time thing but it's hard to believe for me at this point in time.

*Joubert/COACH syndrome (Mason has colobomas, developmental delay, incoordination and facial features somewhat similar to this syndrome as well; if neither of the first two options are evident this one is another possibility (when he has an MRI later this year they will try to rule it out with more specific pictures of his brain). If this is the problem it is likely a combo of mutated genes given by BOTH Brian and I and means the deletion is probably not the issue (though it still could be if the deletion also causes this syndrome and researchers haven't discovered that gene connection yet).

I also asked the team about a study I read about where National Institutes of Health docs would check his entire genome for mutations instead of having to just guess where the problem is out of so many possibilities. They are providing Mason's info to the NIH to see if he would qualify for the study. The advantage of this would be one testing session that would let us know all the possible mutations instead of him having to have repeated testing as he grows to investigate various possibilities. The disadvantage is we may find out "TMI" (more than we ever wanted to know about what could happen with other problems he may or may not have), and we would have to most likely go to the NIH in New England for the testing.

Why does it matter? Some of these syndromes bring with them certain severe but subtle conditions that no one would even know to test for unless they know you have that syndrome. That means, without knowing the underlying condition, things that are severe could pop up without warning, too late to do anything about it, whereas if we know what to watch out for, we can be pre-emptive about screenings. That is the main reason we'd like to know what we're dealing with - to get him the best health care possible without having to wait for things to surprise us - to the extent possible (we know there will ALWAYS be surprises with Mason, and in life in general).

Is it genetic? We may never know this side of Heaven. What we do know...Mason is a joy and a treasure and he has the happiest disposition and attitude of anyone I know :D See for yourself...

"Our mouths were filled with laughter, our tongues with songs of joy. Then it was said among the nations, “The LORD has done great things for them.” Ps. 126:2

Mason's Mix

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