Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to rheumatoid arthritis ?
    ### Response:
    Rheumatoid arthritis probably results from a combination of genetic and environmental factors, many of which are unknown.  Rheumatoid arthritis is classified as an autoimmune disorder, one of a large group of conditions that occur when the immune system attacks the body's own tissues and organs.
    