This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'Which of the following HLA types is associated with IDDM? \nSelect and explain. \nA. HLA DR3, DR4, B. HLA B27, C. HLA B47, D. HLA DR2', 'role': 'user'}, {'content': "Answer: A \nExplanation: Major susceptibility gene for Type 1 DM is located in the HLA region on chromosome 6. 95% of patients with IDDM express HLA DR3 or DR4. Concordance rate of Type 1 DM in identical twins ranges between 40- 60%. Type 2 DM has a strong genetic component. The concordance of type 2 DM in identical twins is between 70 and 90%. Reference: Harrison's Principles of Internal Medicine, 18th Edition chapter 344.", 'role': 'assistant'}]