Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Achondrogenesis ?
    ### Response:
    Achondrogenesis is a group of severe disorders that are present from birth and affect the development of cartilage and bone. Infants with achondrogenesis usually have a small body, short arms and legs, and other skeletal abnormalities that cause life-threatening complications.
    