How do I tell what type of Jew I am though? And why is Ashkenazi different from Sephardi in a medical sense? Is this something I should be really concerned about? Not many of my mother's family are still alive so I'm not sure how to find out either way. I feel there are some rather large holes in my family history that I ought to do something about.

Bugger about the cost of the tests though. I agree with your point about the patents, too.