Question
A newborn has been suspected of having phenylketonuria based on blood tests, but no abnormalities have been observed yet. What symptoms might phenylketonuria present?
Answer
Phenylketonuria may not manifest clinical symptoms during the neonatal period. Typically, symptoms start to appear when the baby is around 3 to 4 months old, including delayed intellectual development and language disorders. These symptoms tend to become more pronounced over time, with intellectual development and language skills issues becoming more severe. Besides the irreversible nature of delayed intellectual development, other symptoms can be improved or disappear if detected and treated early. Therefore, early diagnosis and treatment can prevent the occurrence of intellectual disabilities.