This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Amino acid Metabolism, Subject name: Pediatrics
True statement regarding a 3-week-old child with phenylketonuria are all, EXCEPT: 
Select and explain. 
A. Provocative protein meal tests help in the diagnosis, B. Tyrosine becomes an essential amino acid in diet, C. Serum phenylalanine is increased and urinary phenyl pyruvate level is elevated, D. Phenylalanine should be completely stopped in diet
D: Phenylalanine should be completely stopped in diet
Answer: D: Phenylalanine should be completely stopped in diet 
Explanation: In Phenylketonuria, low phenylalanine diet is used (Because phenylalanine is not synthesized endogenously, small amounts of phenylalanine should be added to the diet to prevent phenylalanine deficiency.) Serum and urine phenylalanine and its metabolites are increased Tyrosine becomes an essential amino acid Blood for screening should be obtained after 24-48 hrs (Protein feeding) to prevent false -ve result. C/F: Microcephaly Epilepsy Musty body odour Reduced skin/hair/eye pigmentation