Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) hypochondrogenesis ?
    ### Response:
    Hypochondrogenesis is a rare, severe disorder of bone growth. This condition is characterized by a small body, short limbs, and abnormal bone formation (ossification) in the spine and pelvis.  Affected infants have short arms and legs, a small chest with short ribs, and underdeveloped lungs.
    