Phenylketonuria is a genetic disorder that causes toxic levels of phenylalanine in the blood and central nervous system damage if left untreated. It is characterized by high phenylalanine levels in the blood and causes symptoms like digestive issues, seizures, eczema, and mental retardation. All newborns are screened for phenylketonuria, and if diagnosed, treatment involves restricting phenylalanine intake through diet, monitoring development, and educating parents on special formulas and foods to avoid.

1. PHENYLKETONURIA

2. PHENYLKETONURIA
A. Definition
1. Phenylketonuria is a genetic disorder (autosomal
recessive disorder) that results in central nervous
system damage from toxic levels of phenylalanine
(an essential amino acid) in the blood.
2. It is characterized by blood phenylalanine levels
greater than 20 mg/dL (normal level is 1.2 to 3.4
mg/dL in newborns and 0.8 to 1.8 mg/dL thereafter).
3. All 50 states require routine screening of all
newborns for phenylketonuria.

3. B. Signs And Symptoms
1. In all children
a. Digestive problems and vomiting
b. Seizures
c. Musty odor of the urine
d. Mental retardation
2. In older children
a. Eczema
b. Hypertonia
c. Hypopigmentation of the hair, skin, and irises
d. Hyperactive behavior

4. C. Interventions
1. Screening of newborn infants for phenylketonuria:
The infant should have begun formula or breast milk
feeding before specimen collection.
2. If initial screening is positive, a repeat test is
performed, and further diagnostic evaluation is
required to verify the diagnosis.
3. Rescreen infants by 14 days of age if the initial
Screening was done before 48 hours of age.
4. If phenylketonuria is diagnosed, prepare to
implement the following:

5. a. Restrict phenylalanine intake; high-protein foods
(meats and dairy products) and aspartame are avoided
because they contain large amounts of phenylalanine.
b. Monitor physical, neurological, and intellectual
development.
c. Stress the importance of follow-up treatment.
d. Encourage the parents to express their feelings
about the diagnosis and discuss the risk of
phenylketonuria in future children.

6. e. Educate the parents about use of special preparation
formulas and about the foods that contain
phenylalanine.
f. Consult with social care services to assist the parents
with the financial burdens of purchasing special
prepared formulas.