system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Defect in phenylketonuria
assistant
The correct answer is  In this condition phenylalanine can&;t be conveed to tyrosine, so phenylalanine accumulates and it&;s level in blood is elevated.Ref: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 236, fig 18.1