General Information for Families
Phenylketonuria (PKU) is a hereditary disease that is caused by the lack of a liver enzyme required to digest phenylalanine. Phenylalanine is an amino acid that is most commonly found in protein containing foods such as meat, cow's milk, over the counter infant formulas (both regular and soy) and breast milk.
Inheritance and Frequency
The gene defect for phenylketonuria is an autosomal recessive genetic trait and is unknowingly passed down from generation to generation. This faulty gene only emerges when two carriers have children together and pass it to their offspring. For each pregnancy of two such carriers, there is a 25% chance that the child will be born with the disease and a 50% chance that the child will be a carrier for the gene defect.
Studies show that 1 of every 17,000 live births will have phenylketonuria.
Signs & Symptoms
Newborns affected by PKU usually do not show any signs of the disease at birth. But within the first few weeks of life they begin to show neurologic disturbances such as epilepsy. Children suffering from undiagnosed PKU also may have an unpleasant, musty smell. It has been shown that almost 90% of affected people have blond hair and blue eyes. Signs also include skeletal changessuch as a small head, short stature, and flat feet. PKU sufferers may also have a skin disorder called eczema.
Long Term Effects
PKU affected children who are not diagnosed and do not eliminate phenylalanine from
the diet, will suffer from irreversible brain damage and mental retardation. Properly
treated individuals should live a normal, healthy life.
Treatment
Treatment of PKU is the elimination of phenylalanine from the diet. Phenylalanine
is commonly found in protein containing foods such as meat. Babies who are diagnosed
with PKU must be immediately be put on a special milk/formula substitute. Later
in life, the diet is mainly vegetarian.
Previously, PKU affected individuals were allowed to go off diet after approximately
12 years of age. However, physicians now recommend that this special diet should
be followed throughout life.
Females affected by PKU, who become pregnant and have stopped following the appropriate
diet, must return to maintaining the diet through the duration of all pregnancies.
Babies of females with PKU who are not on diet during pregnancy can be severely
malformed and mentally retarded. However, females who are on diet have normal, healthy
infants.
Source: savebabies.org
What is phenylketonuria?
(fee-null-kee-tone-yer-ee-ah) Phenylketonuria, called PKU for short, causes the
body to have problems breaking down certain proteins. People with PKU cannot break
down part of the protein called phenylalanine. The body usually breaks down extra phenylalanine that the body doesn’t need. When phenylalanine cannot be broken down,
it builds up and becomes toxic to the organs and the brain. Phenylalanine gets broken
down by an enzyme (a chemical that does a job in the body). A person with PKU is
missing an enzyme, or the enzyme is not working as well as it should. A special
diet low in phenylalanine can prevent most symptoms of PKU.
What causes phenylketonuria (PKU)?
PKU is inherited when both parents pass an abnormal PKU gene to their child. This means both parents are carriers of PKU. Carriers do not experience any health problems related to PKU. When two carriers have children together, there is a one in four (25%) chance for each child to have PKU.
How is phenylketonuria (PKU) detected?
Newborn screening is done on tiny samples of blood taken from the infant’s heel 24-48 hours after birth. After a positive newborn screen, testing at special labs must be done to know for sure if a baby has PKU.
What problems can phenylketonuria (PKU) cause?
Untreated PKU can cause health concerns, behavior problems, and mental retardation.
People with PKU who do not eat phenylalanine have normal growth and development.
What is the treatment for phenylketonuria (PKU)?
PKU can be treated. People with PKU should not eat phenylalanine and should drink
a special formula. The diet is monitored to make sure that very small amounts of
phenylalanine are eaten. The treatment is life-long. For children who have PKU:
- The child should be cared for by a primary care doctor, a pediatric metabolic specialist, and a dietician. These health professionals give the child good medical care and educate the family about PKU.
- Families are taught to read labels carefully when shopping for food. Many prepared foods have hidden ingredients containing phenylalanine. Special low-phenylalanine foods and recipes are available from certain companies and parent support groups.
- Treatment for PKU is life-long, and a child with PKU should see a doctor regularly.
Source: Minnesota Newborn Screening Program
National and State Specific Family Resources
View National and State Specific Family Resources
Phenylketonuria (PKU) Prevalence by State
The Region 4 Newborn Screening Data, summarized annually, provides detailed data on newborn screening results within Illinois, Indiana, Kentucky, Michigan, Minnesota, Ohio and Wisconsin. It is provided here to: assist families and physicians in knowing the relative number of confirmed annual cases for the disorder within each state and how it compares to other states in the region. assist families and specialists across states in connecting with specialists who may have experience treating a specific rare disorder. It is important to note that ongoing developments in the sophistication of technology allows states to progressively increase the number of disorders they screen in their program.
| 2005 Confirmed Cases | ||||||||
| State: | IL | IN | OH | MI | WI | MN | KY | TOTALS |
| Total Births: | 175659 | 85570 | 144509 | 124942 | 70934 | 71058 | 52222 | 724894 |
| Total Specimens: | 182799 | 107983 | 151193 | 133680 | 74887 | 73857 | 0 | 724399 |
| 2005 | 9 | 11 | 8 | 3 | 5 | 6 | 4 | 46 |
| 2004 Confirmed Cases | ||||||||
| State: | IL | IN | OH | MI | WI | MN | KY | TOTALS |
| Total Births: | 177603 | 87942 | 142023 | 134103 | 66625 | 70579 | 50930 | 729805 |
| Total Specimens: | 183727 | 107852 | 151296 | 127572 | 68895 | 71791 | 53583 | 764716 |
| 2004 | 9 | 8 | 0 | 12 | 5 | 0 | 3 | 37 |
| 2003 Confirmed Cases | ||||||||
| State: | IL | IN | OH | MI | WI | MN | KY | TOTALS |
| Total Births: | 182590 | 86382 | 151983 | 130937 | 70053 | 70157 | 55281 | 747383 |
| Total Specimens: | 185033 | 109133 | 152211 | 128970 | 73362 | 71095 | 53381 | 773185 |
| 2003 | 5 | 6 | 0 | 5 | 2 | 0 | 3 | 21 |
| 2002 Confirmed Cases | ||||||||
| State: | IL | IN | OH | MI | WI | MN | KY | TOTALS |
| Total Births: | 180622 | 84618 | 148720 | 129967 | 68560 | 68025 | 54233 | 734745 |
| Total Specimens: | 184033 | 109360 | 152561 | 127978 | 71634 | 67839 | 52775 | 766180 |
| 2002 | 17 | 4 | 0 | 3 | 4 | 0 | 2 | 30 |
