Question

Which of the following statements concerning phenylketonuria (PKU) is true? A. For those affected, dietary restrictions are critical later in life. B. It is interesting to researchers because it does not require an interaction of genes and environment to be expressed. C. Left untreated, it can cause intellectual disability. D. It manifests due to excessive intake of fatty foods.

Answer 1

The true statement about phenylketonuria (PKU) is that if left untreated, it can lead to intellectual disability due to toxic accumulation of phenylalanine in the body. A strict diet low in phenylalanine is crucial for managing the disorder.

Step-by-step explanation:

The question concerns the genetic disorder phenylketonuria (PKU). The correct statement concerning PKU is: C. Left untreated, it can cause intellectual disability. PKU is caused by insufficient activity of the enzyme phenylalanine hydroxylase. This enzyme is responsible for converting the amino acid phenylalanine into tyrosine. When it is lacking, phenylalanine accumulates to toxic levels in the body, potentially causing damage to the central nervous system and leading to symptoms like intellectual disability, neurological development delays, hyperactivity, seizures, rash, tremors, and uncontrolled movements. Individuals with PKU must adhere to a strict diet low in phenylalanine throughout their lives to prevent these symptoms.

Answer 2

The correct answer would be C. Left untreated, it can cause intellectual disability.

Phenylketonuria (PKU) is a rare autosomal recessive disorder caused by a defect in a gene responsible for making phenylalanine digesting enzyme.

This defect leads to the lack or deficiency of this enzyme in the body. Consequently, phenylalanine builds up in the body.

People with this disorder are usually put on a restricted diet which restricts protein-rich food (such as milk, meat, cheese etc as they contain amino acid phenylalanine) from their meals.

Untreated PKU can cause various complications such as brain damage (intellectual disability), neurological problems, major health and development problems etc.