There's a new paper out on Down syndrome that I thought I'd share because it demonstrates several points that I think are relevant to PWS. First, it shows how even complex genetic syndromes can be dissected down to the molecular pathways. Further, it demonstrates that understanding which pathways are disrupted can lead to therapeutic interventions; again demonstrating the shift in the field of genetics from just describing syndromes to trying to develop therapies that mitigate the symptoms. The availability of a good mouse model where one can begin to test the effects of interventions is also a key (and a problem in PWS). Although mice are quite different than humans, mouse models are a good place to demonstrate that your therapeutic approach might have the effect youâ€™d hoped for. Finally, this paper demonstrates the possibility that brain development can be tweaked, even after birth, and this may have a beneficial effect. Here they've defined what pathways lead to the smaller brain that is typical of DS a particular cell type in the brain doesn't multiply normally. They then treat newborn DS mice with a drug to encourage the growth of those cells, and the brains of the treated DS mice develop in a manner similar to normal. What they don't do in this paper is demonstrate that the increased cell growth in the brain made the mice smarter, nor do they address the question of whether the intervention can work after the newborn period (I'm sure they are busy with those questions now) but as far as I know it's the first demonstration of a potential therapeutic intervention that may affect brain development in DS.
Defective cerebellar response to mitogenic Hedgehog signaling in Down syndrome mice. Roper RJ, Baxter LL, Saran NG, Klinedinst DK, Beachy PA, Reeves RH. Proc Natl Acad Sci U S A. 2006 Jan 31;103(5):1452-6, 2006.