This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Maternal and child care, Subject name: Social & Preventive Medicine
[{'content': 'Guthrie test is done in neonates for mass screening of \nSelect and explain. \nA. Neonatal hypothyroidism, B. Hemoglobinopathies, C. Phenylketonuria, D. CDH', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Phenylketonuria is a disorder of amino acid metabolism. This is an autosomal recessive trait in babies who are homozygous with a deficiency in the enzyme phenylalanine hydrolase which normally conves phenylalanine to tyrosine. Mass screening of blood phenylalanine in neonates is performed by the Guthrie test. Ref: Park; 23rd ed; Pg 535', 'role': 'assistant'}]