Difficulty: Easy
Correct Answer: phenylalanine in the diet is restricted
Explanation:
Introduction / Context:
PKU is a classic example of how genetics and nutrition intersect. Without treatment, accumulation of phenylalanine and its metabolites damages the developing brain. Early detection and dietary management prevent severe outcomes.
Given Data / Assumptions:
Concept / Approach:
The therapeutic goal is to keep blood phenylalanine in a safe range by restricting dietary phenylalanine, found in high-protein foods and aspartame. Tyrosine becomes conditionally essential and is supplemented. Lifelong adherence optimizes cognitive outcomes.
Step-by-Step Solution:
Identify toxic substrate: phenylalanine accumulation causes harm.Treatment principle: substrate restriction and product supplementation (tyrosine).Implement low-phenylalanine diet; avoid aspartame; use medical formulas.Thus the correct intervention is phenylalanine restriction.
Verification / Alternative check:
Clinical studies show normalized development when dietary Phe is controlled from infancy. Elevated phenylalanine correlates with poorer IQ and executive function.
Why Other Options Are Wrong:
Common Pitfalls:
Assuming diet can be liberalized in adulthood; evidence supports lifelong management. Hidden Phe sources (sweeteners) can be overlooked.
Final Answer:
phenylalanine in the diet is restricted
Discussion & Comments