Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Limb-girdle muscular dystrophy ?
    ### Response:
    Limb-girdle muscular dystrophy is a group of disorders which affect the voluntary muscles around the hips and shoulders. The conditions are progressive, leading to a loss of muscle strength and bulk over a number of years. Onset may occur in childhood, adolescence, young adulthood, or even later.
    