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: Pediatrics
[{'content': 'A child has tnicrocephaly, blue eyes, Fair skin, and Mental retardation, Ferric chloride test is positive.What is the likely diagnosis - \nSelect and explain. \nA. Phenylketonuria (PKU), B. Homocystinuria, C. Tyrosinosis, D. Alkaptonuria', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Clinical manifestations of phenylketonuria \n\nNormal at birth\nSymptoms occur after 1 months -\n\n\nMental retardation → Not present at birth, develops gradually.\nNeurological signs Irritability, tremors, convulsions, hyperkinesis and muscular hypertonia & exaggerated reflex.\nBlond hair, blue iris, fair skin.\nMusty or mousy body odor.\nVomiting\nMicrocephaly\nEnamel hypoplasia & Growth retardation', 'role': 'assistant'}]