New York Times recently published an article about the work of Dr Butt from Stanford University. He and an increasing number of doctors are starting to group diseases not by their symptoms as in classical medicine, but by their genetic underpinnings.
While I can’t say much about the medical relevance, this work gives rise to an interesting visualisation. Shown is a set of diseases which are related to each other by there genetic similarity. Each disease is represented by a circle with a size proportional to the number of genes involved.