Considering that there are now 4,000 to 5,000 tests for heritable conditions, the question of how good is any test if it doesn't lead to actionable results is on the mind of a lot of people in the consumer genetic testing industry. Scripps' Eric Topol is conducting an experiment to see if taking a test (in this case, they're using Navigenics) will spur people to actually improve their lifestyles. Most experts still urge caution. If you're not taking the test under genetic counseling supervision, you might as well skip it, says one.