Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) craniometaphyseal dysplasia ?
    ### Response:
    Craniometaphyseal dysplasia is a rare condition characterized by progressive thickening of bones in the skull (cranium) and abnormalities at the ends of long bones in the limbs (metaphyseal dysplasia). Except in the most severe cases, the lifespan of people with craniometaphyseal dysplasia is normal.
    