Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Porphyria ?
    ### Response:
    Porphyrias are a group of genetic disorders caused by problems with how your body makes a substance called heme. Heme is found throughout the body, especially in your blood and bone marrow, where it carries oxygen.     There are two main types of porphyrias.
    