Phenylketonuria (PKU) is a rare genetic condition that affects babies for life

The body is unable to break down phenylalanine, which builds up in the blood and brain. High levels of phenylalanine damage brain cells.

PKU is treated with a special low-protein diet to reduce levels of phenylalanine in the body and prevent brain damage.

PKU doesn't usually cause any symptoms if treatment is started early. If PKU isn't treated, damage to the brain and nervous system can lead to:

• learning disabilities
• behavioural difficulties

苯丙酮尿