Munson Health
 
Phenylketonuria

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by Marlow A

(PKU)

 

Symptoms

If detected and treated early, PKU symptoms may never appear. If untreated, one or more of the following symptoms of PKU may appear by the first birthday:
  • Intellectual disability
  • Seizures
  • Hyperactivity and behavioral problems
  • Small head size
  • Vomiting
  • Eczema or rash
  • Musty odor
  • Light coloring
  • Progressive development delay
  • Self-mutilation
 

Treatment

PKU is not curable, but it is treatable with a special diet beginning at birth.
Women with PKU must follow the diet strictly both before and during pregnancy. A phenylalanine level < 6 milligrams/deciliter (mg/dL) [< 363 micromole/liter (µmol/L)] must be maintained to prevent brain damage in the unborn baby.
Pregnancy
Fetus and mother blue
Women with PKU need to follow a strict diet while pregnant to avoid serious birth defects.
Copyright © Nucleus Medical Media, Inc.

Low-Phenylalanine Eating Pattern

This strict diet significantly reduces the intake of phenylalanine to a level that a person with PKU can handle without seeing harmful effects. Newborns require 40-60 mg/kg/day of phenylalanine to maintain adequate growth. For most older children and adults with PKU, the safe range is 200-400 mg of phenylalanine per day. The diet consists of:
  • Drinking phenylalanine-free medical formula, which provides calories, protein, vitamins, and minerals without phenylalanine. Phenylalanine-free medical formulas are manufactured for infants, children, and adults and are the most important feature of the diet for PKU.
  • Starches, including bread, potatoes, corn, and beans must be limited.
  • Eliminating high-protein foods such as milk, meat, fish, chicken, pork, eggs, beans, and nuts.
  • Eliminating foods and beverages made with aspartame, an artificial sweetener that contains phenylalanine.

Medications

Your doctor may advise medication. Sapropterin dihydrochloride may be used to reduce your phenylalanine levels.
Part of the treatment plan for PKU is regular monitoring of the level of phenylalanine in the blood. During infancy, the pediatrician may monitor the blood frequently, as often as once or twice a week. Over time, blood monitoring may not be needed as frequently. The treatment goal is to keep the level of phenylalanine in the blood in the safe range between 2-6 mg/dL (121-363 µmol/L). The doctor or registered dietitian may also perform an occasional diet analysis to calculate the amount of phenylalanine being consumed and to check for potential nutrient deficiencies.
Part of the treatment plan for PKU is regular monitoring of the level of phenylalanine in the blood. During infancy, the pediatrician may monitor the blood frequently, as often as once or twice a week. Over time, blood monitoring may not be needed as frequently. The treatment goal is to keep the level of phenylalanine in the blood in the safe range between 2-6 mg/dL (121-363 µmol/L). The doctor or registered dietitian may also perform an occasional diet analysis to calculate the amount of phenylalanine being consumed and to check for potential nutrient deficiencies.
 

RESOURCES

National PKU News
http://www.pkunews.org

NIH Genetics Home Reference
http://ghr.nlm.nih.gov

 

CANADIAN RESOURCES

Canadian PKU and Allied Disorders
http://canpku.org

Sick Kids
http://www.sickkids.ca

 

References


What is PKU? University of Washington PKU Clinic website. Available at http://depts.washington.edu/pku/about/whatispku.html. Accessed September 4, 2014.


Phenylketonuria (PKU) EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated July 24, 2014. Accessed September 4, 2014.


Phenylketonuria: screening and management [National Institutes of Health Consensus Statement, October 16-18, 2000]. National Institutes of Health website. Available at http://consensus.nih.gov/2000/2000Phenylketonuria113html.htm. Accessed September 4, 2014.


1/21/2014 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Lindegren ML, Krishnaswami S, et al. Adjuvant treatment for phenylketonuria (PKU). Comparative Effectiveness Reviews. 2012;56.

 

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