Final answer:
Phenylketonuria (PKU) is a hereditary disorder caused by the absence of the enzyme phenylalanine hydroxylase, leading to the accumulation of phenylalanine and potential neurological problems.
Step-by-step explanation:
The hereditary disorder caused by the absence of the enzyme that converts the amino acid phenylalanine to tyrosine is known as Phenylketonuria (PKU). In individuals with PKU, a genetic mutation leads to a defective enzyme called phenylalanine hydroxylase, which normally functions to break down phenylalanine. The resulting accumulation of phenylalanine can lead to various health issues, including intellectual disability, seizures, and other neurological problems if not managed with a controlled diet.
This disorder is an example of an enzyme-deficiency disorder, a category of metabolic disorders characterized by the absence or malfunctioning of a specific enzyme due to a genetic mutation. Individuals with PKU inherit two copies of the mutated gene, one from each parent, leading to an autosomal recessive inheritance pattern.