Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Familial hypertrophic cardiomyopathy ?
    ### Response:
    Familial hypertrophic cardiomyopathy (HCM) is an inherited heart condition characterized by thickening of the heart muscle. The thickening most often occurs in the muscle wall that separates the left and right ventricles from each other (interventricular septum).
    