Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) atelosteogenesis type 2 ?
    ### Response:
    Atelosteogenesis type 2 is a severe disorder of cartilage and bone development. Infants born with this condition have very short arms and legs, a narrow chest, and a prominent, rounded abdomen. This disorder is also characterized by an opening in the roof of the mouth (a cleft palate), distinctive facial features, an inward- and upward-turning foot (clubfoot), and unusually positioned thumbs (hitchhiker thumbs).
    