(PKU) is a genetically inherited birth defect that causes an unwanted buildup
of the amino acid phenylalanine in the blood, which becomes toxic to the brain.
This buildup occurs because the enzyme that routinely converts one amino acid,
phenylalanine, to another amino acid, tyrosine, is absent or deficient.
Phenylalanine then accumulates in the blood and is toxic to brain tissue.
PKU at Birth
born in the United States are screened for PKU with a blood test so that
treatment can begin immediately and prevent the adverse side effects of the
condition, such as declining intelligence, neurological deterioration, stunted
growth, hyperactivity and seizures. A treatment team typically consists of a
metabolic dietitian, physician, geneticist and psychologist as an infant is
monitored during different phases of growth and development in childhood to an
strict diet limited in phenylalanine is the main treatment for PKU. Phenylalanine
is found in most protein-containing foods such as milk, eggs, cheese, nuts,
soybeans, chicken, beef, pork, beans and fish. "An infant will have to
consume a special phenylalanine-free formula for the first year of life," says
Sarah Krieger, MPH, RDN, spokesperson for the Academy of Nutrition and
Dietetics. However, some breast milk can be used in limited amounts.
Unique Meal Plan
the infant grows and becomes developmentally ready for solid foods, a dietitian
with expertise in PKU will create a unique menu for the child. "The
metabolic dietitian can create meal plans with modified food sources of protein
low in phenylalanine and high in tyrosine, while providing adequate calories,
vitamins and minerals to support growth," says Krieger. Because so many
foods are off limits with PKU, the meal plans include special formulas which
are often the primary source of calories and essential nutrients. Special
phenylalanine-free foods are available for children and teens with PKU. The
metabolic dietitian will create individual eating plans and modify them as
needed to promote healthy growth and development.
diet needs to be followed for life. "The individual with PKU will require
blood monitoring to maintain serum phenylalanine levels," says Kreiger. In
conjunction with blood monitoring, regular review of diet records or food
journals and growth charts the metabolic dietitian will make adjustments to the
eating plan as needed.
of children with PKU need to be creative with foods and use available PKU
cookbooks. Get help with menu planning from the metabolic dietitian and plan
ahead for eating out, school lunches, potlucks, trips and vacations, and other
special events. Try to center special occasions around activities rather than food,
and encourage your child to be part of the management of his or her diet as
early as possible. "A skilled dietitian, physician and psychologist team
can address social issues with each stage of life," says Kreiger. "Knowledge
is power and the more parents, and eventually the child, know how to live with
PKU, then a healthy, productive life is possible."