Blogspam.

Original article (to which ScienceDaily has added precisely nothing): http://www.washington.edu/news/articles/abundance-of-rare-dn...

Underlying paper in Science (paywalled): http://www.sciencemag.org/content/early/2012/05/16/science.1...

Brief writeup from Nature discussing this paper and a couple of others on similar topics: http://www.nature.com/news/humans-riddled-with-rare-genetic-...