This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics, Subject name: Medicine
[{'content': 'DNA topoisomerase 1 autoantibody is specific for? \nSelect and explain. \nA. Limited cutaneous systemic sclerosis, B. Mixed connective tissue disease, C. Diffuse scleroderma, D. SLE', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Scl-70 antibodies are associated with more severe scleroderma disease. Anti-topoisomerase antibodies can be classified according to their immunoglobulin class (IgM, IgG or IgA). IgG-ATA is found most frequently in scleroderma, with IgA being quite common but IgM very infrequent. Ref Robbins 9/e pg 230', 'role': 'assistant'}]