Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Cleidocranial dysplasia ?
    ### Response:
    Cleidocranial dysplasia is a condition that primarily affects the development of the bones and teeth. Characteristic features of this condition include underdeveloped or absent collarbones (clavicles) and delayed closing of the spaces between the bones of the skull (fontanels).
    