It’s often silent but can be a deadly killer. Hypertrophic cardiomyopathy is a genetic condition that occurs in 1 in 500 people. Dr. Said Alsidawi, a Mayo Clinic cardiologist, says the problem is that many people don’t even know they have it because they have no symptoms. And in many cases, the first presentation is sudden cardiac death. Watch: The Mayo Clinic Minute Journalists: Broadcast-quality video (1:07) is in the downloads at the end of…