This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inborn Errors of Metabolism, Subject name: Pediatrics
[{'content': 'Ectopia lentis in a child is seen in which of the following diseases? \nSelect and explain. \nA. Sarcoidosis, B. Homocystinuria, C. Alkaptonuria, D. Urea cycle defects', 'role': 'user'}, {'content': 'Answer: B \nExplanation: b. Homocystinuria(Ref: Nelson 20/e p 326)Ectopia lentis is one of the features of Homocystinuria, where the direction of lens subluxation is infero-medial, unlike supero-lateral subluxation in Marfan syndrome.', 'role': 'assistant'}]