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: Biochemistry
[{'content': "An infant presents to OPD with a history of vomiting and poor feeding. Musty odor is present in baby's urine. Guthrie test was done and found to be positive. The most likely diagnosis is? \nSelect and explain. \nA. Phenylketonuria, B. Alkaptonuria, C. Tyrosinemia, D. Maple syrup urine disease", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Clinical Presentation of Phenylketonuria\xa0\n\nThe affected infant is normal at birth.\xa0\nProfound intellectual disability develops gradually if the infant remains untreated.\xa0\nVomiting, sometimes severe enough to be misdiagnosed as pyloric stenosis.\xa0\nOlder untreated children become hyperactive with autistic behaviors\xa0including purposeless hand movements, rhythmic rocking and athetosis.\xa0\nThe infants are lighter in their complexion than unaffected (Phenylalanine not converted to Tyrosine, so decreased melanin synthesis).\nThese children have an unpleasant mousy or musty odor of phenylacetic acid.\n\nLab Diagnosis of PKU\nGuthrie\xa0Test (Bacterial Inhibition Assay of Guthrie).\n\nRapid screening test in the blood sample.\nFirst method used for this purpose.\n\nReference- Harper’s illustrated biochemistry. 30th edition page -304', 'role': 'assistant'}]