“Doctor, should I get one of those big gene tests so I’ll know  what I’m going to get in the future?” That’s a very common question now. People see friends posting DNA results online, hear about celebrities like Angelina Jolie having preventive surgery for BRCA genes, or know a family member who had cancer or a heart attack “out of the blue.” It’s natural to wonder if your genes can give you a clear warning—or a clean bill of health. Genomic testing can  be a powerful tool fo