PKU NCLEX Quiz: What's True of Phenylketonuria?
Quick, free quiz with NCLEX questions on PKU. Instant feedback and short rationales.
This quiz helps you check your knowledge of phenylketonuria for the NCLEX, with clear questions and instant feedback. You will practice diet limits, newborn screening basics, and the PAH enzyme defect in simple steps. For related practice, try the genetic disorders quiz and build metabolic skills with diabetes nclex questions.
Study Outcomes
- Identify True Characteristics of PKU - Recognize which of the following is true of PKU by recalling key aspects of phenylketonuria pathophysiology and phenotypic presentation. 
- Differentiate Clinical Presentation and Lab Findings - Distinguish common symptoms and diagnostic results associated with PKU, including elevated phenylalanine levels and related biochemical markers. 
- Apply Dietary and Therapeutic Interventions - Outline appropriate low”phenylalanine diet plans and nursing interventions to manage PKU based on current NCLEX PKU questions guidelines. 
- Analyze NCLEX-Style PKU Questions - Develop strategies to approach PKU NCLEX question formats effectively and improve accuracy under exam conditions. 
- Evaluate Test-Prep Performance - Use instant quiz feedback to assess proficiency in phenylketonuria NCLEX practice and identify areas for further study. 
Cheat Sheet
- Pathophysiology of PKU - Phenylketonuria results from a deficiency of phenylalanine hydroxylase (PAH), blocking the conversion of phenylalanine to tyrosine and leading to toxic buildup of phenylalanine in the blood and brain. Remember the simple formula: Phe --(PAH, BH₄)→ Tyr; if PAH is missing, Phe accumulates. When you see an NCLEX PKU question asking which of the following is true of PKU, first recall this core enzymatic defect. 
- Clinical Manifestations - Untreated PKU often presents with intellectual disability, seizures, eczema, and a characteristic musty body odor due to excess phenylacetic acid. Use the mnemonic "MUSTY PHenylketonuria" (MUSTY = musty odor, U = unusual behavior, S = seizures, T = tremors, Y = yellowish hair/pale skin). This quick phrase helps you ace that PKU NCLEX question every time. 
- Newborn Screening - All newborns undergo a heel-prick blood test 24 - 48 hours after birth to measure phenylalanine levels, enabling early diagnosis and intervention. Early detection through this phenylketonuria NCLEX practice point prevents irreversible neurotoxicity and ensures timely dietary management. Remember: screening within the first week of life is crucial for best outcomes. 
- Dietary Management - A lifelong low-phenylalanine diet supplemented with tyrosine is the cornerstone of therapy, controlling plasma phenylalanine levels between 120 - 360 µmol/L. A handy tip is to track daily Phe intake with specialized formulas and low-protein foods; typical targets hover around 200 - 500 mg of Phe per day. This PKU test prep fact underpins many NCLEX PKU questions on diet and nutrition. 
- Genetics & Counseling - PKU is inherited in an autosomal recessive pattern, so parents who are carriers have a 25% chance of an affected child with each pregnancy. Genetic counseling and carrier screening are recommended for at-risk families to discuss recurrence risks and prenatal testing options. Keeping this inheritance pattern in mind will help you select which of the following is true of PKU in any exam scenario.