Linda Shrieves has written an article in the Orlando Sentinel that should be required reading for all genealogists as well as for practically everyone else. She writes (in part):
Genealogy has long been used to trace family histories -- to find out who your ancestors were and where they came from. But now some people are using genealogy to learn whether they're at risk for diseases ranging from diabetes to cancer to heart disease.
Interesting article. You can read all of it at: http://www.orlandosentinel.com/features/lifestyle/orl-medicalhistory08dec09,0,2623001.story.