DS research piggybacks on Alzheimer's

Maybe I was unduly negative in my last post re prospects for DS research. What I forgot to take into account is the fact that a lot of research into Alzheimers seems to impact research into DS, too. And there's no shortage of people with -- or likely to develop -- Alzheimers. "Thank you", Baby Boomers?

There seems to be a lot of similarity in brain chemistry between people with DS and people with Alzheimers. Many of the medicines being tested on people with DS were originally developed to treat Alzheimers. So hopefully this means that the current population of people with DS -- who will probably be the last? -- will continue to receive new treatments.

New prenatal test spells doom for people with Down Syndrome

Yesterday's business news made me terribly sad, but also admittedly happy.
http://www.signonsandiego.com/news/business/biotech/20080605-9999-1b5sequenom.html

You see, I have a child with Down Syndrome (DS) and I'm glad my wife and I didn't know beforehand. We had the typical amount of prenatal testing and nothing serious was found. Now this new test from Sequenom may dramatically reduce the number of children born with DS. In the abstract I think this would be great. But I also think it will negatively affect the prospects for people who already have DS. As the population of people with DS declines so will the potential ROI on any new drugs/treatments. Am I being unduly negative here?