Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) limb-girdle muscular dystrophy ?
    ### Response:
    Limb-girdle muscular dystrophy is a term for a group of diseases that cause weakness and wasting of the muscles in the arms and legs. The muscles most affected are those closest to the body (proximal muscles), specifically the muscles of the shoulders, upper arms, pelvic area, and thighs.
    