Is hypertrophic cardiomyopathy hereditary? Sex-linked or recessive?

Yes. Hypertrophic cardiomyopathy is almost always hereditary, being an autosomal dominant condition. It commonly runs in families, thus the importance of evaluating everyone in the immediate family (siblings or children) with echocardiography since hypertrophic cardiomyopathy is a potentially fatal condition, particularly in young people and young athletes. Detection is the key to saving a life.
Yes. Hypertrophic cardiomyopathy can be inherited in an autosomal dominant way; this nevertheless does not mean that if one of your parents has it you are doomed to have the condition. You could have the bad gene in your dna but not manifest the condition or you could have received the good gene. Ask your doctor to send you and your affected family member for genetic testing which is now available.