Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Congenital short femur ?
    ### Response:
    Congenital short femur is a rare type of skeletal dysplasia, a complex group of bone and cartilage disorders that affect the skeleton of a fetus as it develops during pregnancy. Congenital short femur can vary in severity, ranging from hypoplasia (underdevelopment) of the femur to absence of the femur.
    