Question

What causes the deficits found in children with phenylketonuria (PKU)? 1. They are unable to synthesize melanin, thyroxine and catecholamines. 2. They are unable to synthesize renin, erythropoietin and antidiuretic hormone. 3. They are unable to synthesize aldosterone, cortisol and androgens. 4. They are unable to synthesize neurotransmitters gamma aminobutyric acid (GABA) and acetylcholine.

Answer 1

The correct answer is 1. They are unable to synthesize melanin, thyroxine and catecholamines.

Step-by-step explanation:

Phenylketonuria is a genetic disorder in which an essential amino acid which is called phenylalanine accumulates in the body because the gene that is responsible to synthesize a enzyme that is needed to metabolize phenylalanine gets mutated.

Tyrosine is an amino acid which nonessential and is synthesized from phenylalanine. This tyrosine is an important precursor for melanin, thyroxine, and catecholamines. So children who have phenylketonuria are not able to synthesize melanin, thyroxine, and catecholamines. Therefore the correct answer is 1.

Answer 2

1. They are unable to synthesize melanin, thyroxine and catecholamines

Step-by-step explanation:

Phenylketonuria (PKU), is defined as an inherited disorder that causes error of metabolism due to the inability of body to break down phenylalanine into tyrosine.

It occurs due to the defective gene unable to produce phenylalanine hydroxylase enzymes that convert phenylalanine into tyrosine. Body utilize tyrosine for the biosynthesis of many other proteins such as melanin, thyroxine and catecholamines and perform many other brain function.

Hence, the correct option is 1.