The "slippery-slope" of gene therapy

First, to understand what I'm talking about, read this article:

http://www.dailymail.co.uk/health/article-2368276/Scientists-switch-extra-chromosome-causes-Downs-Syndrome.html

Here is one quote from the article (but, you should really click on the link and read the whole thing):

"Gene therapy has already been used to treat medical problems that result from the presence of one defective gene, but this is the first time that silencing the impact of a whole chromosome has become a possibility."

The news in this article has been shared and re-shared by a good number of parents of children with PWS, on Facebook.  It is definitely exciting news; while the possibilities of gene therapy have been researched for some time, this particular development is one that really resonates in the PWS community.  There is a variety of PWS with which this possibility of turning off - or even turning on - a chromosome or parts of it is especially important: those children who have PWS by uniparental disomy, meaning they have two X (maternal) chromosomes in the 15th pair.  

I can't possibly get deeply into the genetics of this - I'm relatively smart but I'm not a geneticist.  What struck me as I read this article wasn't the miraculous science of it all.  Rather, it was the moral and ethical ramifications of this development that would be faced, I think, down the road.

Does this ability to turn off that extra chromosome - would that mean that when in-utero testing is done, and the tests come back as definitely positive for Down's syndrome, that then the parent(s) would be able to make a choice about their baby?  And by choice I mean, would they then be able to choose to still have the baby, but it would be a baby whose genes had been genetically modified so that they no longer had Down's Syndrome?

If this plan of action became available - what would society feel about parents who chose NOT to have their unborn child's genes genetically modified, and they thus chose to go ahead and give birth to a baby with Down's Syndrome?  If humans develop the ability to fiddle with who the next generations fundamentally are - their genetic makeup - where does that stop?

I would say that pretty much all the parents/caregivers of individuals with PWS would be in favor of their child/family member not  having this frustrating, complex syndrome.  I'm just not sure if we all really want to condone "genetically modified humans".  I do hope that research can silence the hyperphagia for my daughter and all those with PWS...I also think, though, that being able to orchestrate a syndrome-free or disease-free human may have some troubling ramifications.

Later,
Jen