Complications

Untreated PKU can lead to complications in infants, children and adults with the disorder. When mothers with PKU have high blood phenylalanine levels during pregnancy, fetal birth defects or miscarriage can occur.

Untreated PKU can lead to:

• Irreversible brain damage and marked intellectual disability beginning within the first few months of life
• Neurological problems such as seizures and tremors
• Behavioral, emotional and social problems in older children and adults
• Major health and developmental problems