Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Progressive pseudorheumatoid arthropathy of childhood ?
    ### Response:
    Progressive pseudorheumatoid arthropathy of childhood (PPAC) is a disorder of bone and cartilage that affects many joints. Major signs and symptoms include stiff joints (contractures), short stature, and widening of the ends of the finger and toe bones as well as other tubular bones.
    