Is HCM (hypertrophic cardiomyopathy) Genetic?

Now no one in my family has it at all, but I'm just curious. How would one develop it. Where would it come from? Is it only Genetic? And why is it mostly common among Athletes. Oh and I've been hooked up to those heart monitors and the doctor has checked my pulse, i know i don't have it. But I've always been curious.