Newborns with phenylketonuria do not have any typical clinical manifestations, and symptoms usually begin to appear at 3 to 6 months of age and become apparent at 1 year of age. The main manifestations are abnormal development of the nervous system, abnormal skin color and having urine with smell.
1. Neurological system: intellectual development is delayed, and mental behavioral abnormalities, such as excitability, depression, low self-esteem and isolation, are present. Minor epileptic seizures may be present, and a few show increased muscle tone and hyperreflexia of tendons.
2. Skin: the melanin synthesis in the body of the affected children is insufficient, the skin is fair, and the hair turns from black to yellow. Most children have eczema.
3. Body odor: urine and sweat may have a distinct odor of rat urine.
Phenylketonuria is an autosomal recessive genetic disease, which is an inherited metabolic disease that can be diagnosed and treated early. Once diagnosed after newborn screening, treatment should be prescribed immediately, and the younger the age at which treatment is initiated, the better the prognosis tends to be.