Which type of inheritance pattern is observed in PKU?

Phenylketonuria (PKU) is caused by a deficiency in the enzyme phenylalanine hydroxylase, which is necessary for the conversion of phenylalanine to tyrosine. This metabolic disorder leads to the accumulation of phenylalanine in the body, resulting in a variety of serious health issues, including intellectual disability if not managed. The inheritance pattern of PKU is classified as autosomal recessive, meaning that an individual must inherit two copies of the mutated gene—one from each parent—in order to express the condition.

Autosomal recessive conditions are typically characterized by the following features: both parents are usually carriers of the mutated gene but do not show symptoms themselves; there is a 25% chance with each pregnancy that two carrier parents will have an affected child; and the trait may skip generations. In the case of PKU, approximately 1 in 10,000 to 1 in 15,000 live births in the United States are affected, and newborn screening programs have significantly improved early detection and management.

The other inheritance patterns mentioned do not accurately describe PKU. X-linked dominant disorders, for instance, would be expressed in females with only one copy of the mutation and would typically manifest differently. Autos