An individual develops intellectual disability because of a disorder called phenylketonuria. Which of the following occurrences is a cause of the intellectual disability in the individual?
A) The replacement of myelin by hard, fibrous tissue in the individual's neurons
B) The inhibition of normal myelin development in the individual's brain
C) Insulation of the neurons by myelin
D) Myelination of the prefrontal matter of the individual's brain

Question

Quizplus · Accepted Answer

Phenylketonuria (PKU) is a metabolic disorder caused by a deficiency of the enzyme phenylalanine hydroxylase, leading to an accumulation of phenylalanine in the body. High levels of phenylalanine can inhibit normal myelin development in the brain, which is essential for proper nerve function. This disruption in myelination is a key factor in the intellectual disability associated with PKU.

An Individual Develops Intellectual Disability Because of a Disorder Called