Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) generalized arterial calcification of infancy ?
    ### Response:
    Generalized arterial calcification of infancy (GACI) is a disorder affecting the circulatory system that becomes apparent before birth or within the first few months of life. It is characterized by abnormal accumulation of the mineral calcium (calcification) in the walls of the blood vessels that carry blood from the heart to the rest of the body (the arteries).
    