Phenylketonuria (PKU)
Treatment Overview
The main treatment for phenylketonuria (PKU) consists of permanently reducing the amount of protein in the diet. For a few people, medicine may help reduce phenylalanine blood levels when used with a PKU diet.
Protein contains phenylalanine, an amino acid that is essential for normal growth and development. People with PKU lack an enzyme to properly metabolize phenylalanine. Very high levels of phenylalanine in the blood can lead to irreversible brain and nervous system damage.
Experts recommend feeding your newborn a phenylalanine-free formula within 7 to 10 days after birth.4 You may also be able to feed your baby breast milk, but talk to your baby's doctor first. During your baby's first year, blood tests to measure phenylalanine levels are usually done weekly.
Although any brain or nervous system damage that develops is irreversible, problems are less likely to occur if a PKU diet starts by 3 weeks of age. Your baby will most likely grow and develop normally when feedings with low-phenylalanine formula are used. In rare cases, children may have learning or behavior problems (such as slower language development, hyperactivity, anxiety, and poor concentration) despite early treatment.
A reduced-protein diet should be consistently followed throughout life. As your child grows, the diet is individualized and adjusted according to his or her specific needs. Hunger levels, growth, development, behavior, illness, food preferences, and phenylalanine blood levels are all taken into consideration.
A few people may be able to take the medicine sapropterin dihydrochloride (Kuvan) to help lower phenylalanine levels. A PKU diet needs to be followed while this medicine is taken. It's not known if Kuvan helps reduce long-term nervous system problems. And its safety has not been studied in children younger than age 4 or in adults ages 65 and older. Talk to your doctor if you want to know if it's safe for you or your child.
It is important to have regular blood tests to measure phenylalanine levels. From ages 1 to 12, testing is usually done twice a month. After age 12 and throughout adulthood, testing once a month is suggested. High levels of phenylalanine in teens and adults negatively affect IQ (intelligent quotient) and cognitive functions such as awareness, knowledge, thinking, learning, and judgment.
Maternal PKU
The American Academy of Pediatrics and other expert groups offer recommendations and guidelines for preventing and managing PKU in women who are or who may become pregnant. Generally, women who have PKU and want to have a baby need to follow the PKU diet and get enough nutrients to support a growing fetus.
It is best to adopt the PKU diet before becoming pregnant. Mental retardation can occur in as many as half of the children who have mothers with uncontrolled PKU during most of their pregnancy.5, 6 High levels of phenylalanine in the mother during pregnancy can also cause babies to be born with abnormally small heads (microcephaly), growth problems, and congenital heart disease.
Women with PKU who are considering becoming pregnant should also have periodic blood tests, as advised by their health professional, to measure phenylalanine levels. Low levels (below 6 mg/dL) of phenylalanine should be reached at least 3 months before conception. Recommended levels are 2 mg/dL to 6 mg/dL.7 After a woman is pregnant, she should be tested at least once a week until the baby is born.
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| Author: | Debby Golonka, MPH | Last Updated: February 27, 2008 |
| Medical Review: | Michael J. Sexton, MD - Pediatrics Thomas Emmett Francoeur, MDCM, CSPQ, FRCPC - Pediatrics | |
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| Topic Contents | |
| Topic Overview | |
| Symptoms | |
| Exams and Tests | |
 | Treatment Overview |
| Home Treatment | |
| Other Places To Get Help | |
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