Question

What happens when you have a phenylalanine hydroxylase deficiency?

a. It causes phenylalanine to accumulate and is converted instead to phenylpyruvate, instead of Tyrosine at normal levels.
b. Excess production of tyrosine due to increased enzyme activity.
c. Enhanced breakdown of phenylalanine leading to reduced blood levels.
d. Accumulation of phenylalanine, resulting in increased tyrosine levels.

Answer 1

When you have a phenylalanine hydroxylase deficiency, it causes phenylalanine to accumulate and convert to phenylpyruvate instead of Tyrosine at normal levels.

Step-by-step explanation:

When you have a phenylalanine hydroxylase deficiency, it causes phenylalanine to accumulate in the body. This accumulation leads to the conversion of phenylalanine into phenylpyruvate instead of being converted to tyrosine at normal levels. The excess phenylpyruvate can have various negative effects on the body, including neurological signs such as irritability, convulsions, muscular hypertonia, tremors and mental development. It can also result in physical symptoms like blond hair, blurry iris, fair skin, and vulnerability to inflammatory lesions, rashes, and eczema.

Deficiency in phenylalanine hydroxylase leads to elevated levels of phenylalanine in the blood and other tissues, potentially causing toxic effects, including damage to the central nervous system and brain. This can result in developmental delays, intellectual disability, and other neurological symptoms. In individuals with PKU, phenylalanine accumulation also inhibits the metabolic pathways of other amino acids, such as tyrosine and tryptophan, compounding the detrimental effects.