Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Dyggve-Melchior-Clausen syndrome ?
    ### Response:
    Dyggve-Melchior-Clausen (DMC) syndrome is a rare, progressive genetic condition characterized by abnormal skeletal development, microcephaly, and intellectual disability. Only about 100 cases have been reported to date. Skeletal abnormalities may include a barrel-shaped chest with a short truck, partial dislocation of the hips, knock knees, bowlegs, and decreased joint mobility.
    