What are some symptoms of PKU?

Kimberly and Zieve. (2011) [3]

Phenylalanine plays a role in the body's production of melanin, the pigment responsible for skin and hair color. Therefore, infants with the condition often have lighter skin, hair, and eyes than brothers or sisters without the disease.

Other symptoms may include:

·         Delayed mental and social skills

·         Smaller head size than normal

·         Hyperactivity

·         Jerking movements of the arms or legs

·         Mental retardation

·         Seizures

·         Skin rashes

·         Tremors

·         Unusual positioning of hands

If the condition is untreated or foods containing phenylalanine are not avoided, a "mousy" or "musty" odor may be detected on the breath and skin and in urine. The build up of phenylalanine substances in the body results in the odor.