Phenylketonuria (PKU)

What is Phenylketonuria (PKU)?

Phenylketonuria (PKU) is an inherited disorder in which a person is unable to properly metabolize the amino acid phenylalanine. It is caused by a defect in the gene that helps produce the enzyme phenylalanine hydroxylase. When the enzyme is missing or not working properly, the body is unable to process phenylalanine properly. As a result, phenylalanine accumulates in the blood and tissues.

Symptoms Of PKU

If not treated, symptoms of PKU include intellectual disability, seizures, behavioral problems, skin disorders and poor physical growth. Symptoms can also include musty body odor and light-colored skin, hair and eyes. In the severe forms, a person with PKU may develop enlarged liver, heart problems, and ultimately death.

Diagnosis of PKU

PKU is usually diagnosed through a newborn screening test, which is usually performed at 48 hours of life. A blood sample is taken and analyzed for phenylalanine levels. If levels are high, the diagnosis is confirmed through additional tests.

Treatment of PKU

Treatment for PKU usually consists of eating a special diet low in phenylalanine as well as taking a supplement such as Kuvan tablets. Other treatments can include vitamin and mineral supplements, avoiding foods that contain phenylalanine, and regular visits to a dietician or nutritionist.

Complications Of PKU

Possible complications of PKU include:

• Behavioral problems
• Intellectual disability
• Seizures
• Skin disorders
• Heart problems
• Enlarged liver

Prevention Of PKU

Phenylketonuria cannot be prevented. However, women who are carriers of the disorder can be counseled on options regarding genetic testing prior to pregnancy.