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': 'In Hartnup disorder, metabolism of which of the following amino acids is affected? \nSelect and explain. \nA. Tyrosine, B. Tryptophan, C. Phenylalanine, D. Homocysteine', 'role': 'user'}, {'content': "Answer: B \nExplanation: b. Tryptophan(Ref: Nelson's 20/e p 648-649)In Hartnup disorder, there is a defect in transport of monoamino-monocarboxylic amino acids (neutral amino acids), including tryptophan, by intestinal mucosa & renal tubules due to mutation of SLC6A19 gene located on chr 5pl 5", 'role': 'assistant'}]