Question
If a newborn’s phenylketonuria test result is 2.0, is it normal? What are the normal values?
Answer
Normal phenylalanine levels should be between 0.06 and 0.18 mmol/L. Phenylketonuria is a congenital genetic metabolic disease caused by enzyme defects in the breakdown and metabolism of phenylalanine, leading to the accumulation of phenylalanine and ketones, which are then excreted in urine. In the neonatal period, there are usually no obvious symptoms, but after several months, symptoms such as delayed intellectual and growth development, hair discoloration, skin whitening, and a distinctive body odor may appear.