Patient's question:
My baby at home suffers from nausea and vomiting every day, has small red bumps on their face, and cries a lot. After having blood taken for a thorough examination at the hospital, the hospital said the child has phenylketonuria.Doctor's answer:
Phenylketonuria (PKU), a rare disease, is a congenital metabolic disorder caused by a chromosomal gene mutation leading to a deficiency of phenylalanine hydroxylase (PAH) in the liver, resulting in impaired phenylalanine (PA) catabolism and causing damage to the central nervous system. The diagnosis of children primarily relies on the measurement of blood phenylalanine levels, which are often above 20 mg/dL in affected children. The diagnostic basis includes characteristics such as intellectual disability, yellow hair, pale skin, delayed motor and language development in children, elevated blood phenylalanine levels, and exclusion of other diseases that may cause phenylalanine elevation. Active disease screening should be implemented immediately after newborns are born to ensure the timely diagnosis of phenylketonuria before the onset of the disease.