Biochemistry Which of the following clinical laboratory observations is suggestive of Hartnup disease? A 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 💡 Explanation Which of the following clinical laboratory observations is suggestive of Hartnup disease? ✓ Correct Answer: D. High fecal levels of tryptophan and indole derivatives