This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
[{'content': 'Which of the following clinical laboratory observations is suggestive of Hanup disease? \nSelect and explain. \nA. Burnt sugar smell in urine, B. High plasma phenylalanine levels, C. Extremely high levels of citrulline in urine, D. High fecal levels of tryptophan and indole derivatives', 'role': 'user'}, {'content': 'Answer: D \nExplanation: High fecal levels of tryptophan and indole derivatives Hanup disease is autosomal recessive metabolic disorder also known as pellagra like dermatosis. This affect the absorption of nonpolar( neutral ) amino acids specially tryptophan. So there is no absorption of tryptophan.', 'role': 'assistant'}]