What are the names of the disorders for PKU?

Phenylketonuria (PKU) itself is a metabolic disorder, primarily characterized by the inability to metabolize phenylalanine due to a deficiency in the enzyme phenylalanine hydroxylase. While PKU does not have multiple distinct disorders associated with it, it can lead to various complications if untreated, such as intellectual disability and neurological issues. Additionally, there are different forms of PKU, including classic PKU and variant PKU, which differ in severity based on the level of enzyme activity.