What Is Phenylketonuria (PKU)?
General information on phenylketonuria, an inherited metabolic disease, the importance of newborn screening and the role of diet in its management.
Definition and cause
Phenylketonuria (PKU) is an inherited metabolic disease in which the body cannot process phenylalanine, a building block found in protein foods. Unprocessed phenylalanine accumulates in the blood and is harmful, particularly to the developing brain. The disease appears when the altered gene is inherited from both parents.
- Type
- Inherited metabolic disease
- Accumulating substance
- Phenylalanine
- Diagnosis
- Newborn heel-prick screening
- Cornerstone of management
- Special diet and specialist care
Heel-prick screening
In Turkey, all newborns are screened for PKU with a heel-prick blood sample taken in the first days of life, one of the country's longest-established newborn screening programmes. Early diagnosis is vital: when management begins before accumulation starts, children can develop healthily. A high screening value alone does not establish the diagnosis; confirmation tests are performed at specialist centres.
The role of diet
Management is built on a special diet that keeps phenylalanine intake within a target range. Protein-rich foods such as meat, milk and eggs are restricted, and the remaining protein requirement is met with special phenylalanine-free medical nutrition products. Target blood levels vary with age and are monitored with regular tests. In some patients the physician may consider approaches complementary to diet; that decision belongs to the metabolic specialist.
Specialist follow-up
PKU care is provided at centres where paediatric metabolic specialists, dietitians and other disciplines work together. Women with PKU who plan a pregnancy should prepare with their specialists beforehand to bring blood levels into the target range before conception.
This page is intended as general health information; for diagnosis and treatment, please consult your physician.
Frequently asked questions
When is the heel-prick sample taken?
In the first days after birth, usually within 48 to 72 hours. The screening programme covers all newborns and tests for several diseases including PKU.
Can PKU be treated?
PKU can be kept under control with early diagnosis and consistent management. The cornerstone is a special diet, planned individually by the metabolic specialist and dietitian.
Is the PKU diet lifelong?
The current approach is to maintain target blood levels for life. Targets vary with age; monitoring and any relaxation decisions are made only by the specialist.
Which foods contain phenylalanine?
Protein foods, notably meat, poultry, fish, dairy, eggs and legumes. Some sweeteners also contain phenylalanine, and product labels carry a warning to that effect.
Aymed İlaç Sanayi manufactures authorised medicinal products. This page does not contain diagnostic or treatment advice; it is intended as general health information.