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 diseases shows Pleiotropism \nSelect and explain. \nA. Marfan syndrome, B. Sickle cell disease, C. Phenylketonuria, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Pleiotropism - A single gene mutation may have phenotypic effects.', 'role': 'assistant'}]