Phenylketonuria (PKU) is a recessive human disorder in which an individual cannot appropriately metabolize the amino acid phenylalanine. This amino acid is not naturally produced by humans. Therefore, the most efficient and effective treatment is which of the following?
a. Transfuse the patients with blood from unaffected donors.
b. Regulate the diet of the affected persons to severely limit the uptake of the amino acid.
c. Feed them the substrate that can be metabolized into this amino acid.
d. Feed the patients an excess of the missing product.
e. Feed the patients the missing enzymes in a regular cycle, such as twice per week.

Answer

b. Regulate the diet of the affected persons to severely limit the uptake of the amino acid.

Explanation:

This is the effective way of  managing PKU, if diet is not regulated, the blood plasma  Phenylketonuria levels continue to build up  from usual protein consumption. This leads to toxicity of the brain  and brain  dysfunctions. Nausea constipation, fatigues, health headaches are some of the results of the build up.

Therefore to reduce the blood build up of phenylalanine and thus PKU;  Special diet  formulas rich in essential amino acids, and other needed nutrients which may be absent  in phenylalanine low diet  should be  adopted. Amino acids substitutes notably Tyrosine which  is lacking  from  failure of  phenyalanine breakdown in  phenylketouria is heavily  supplemented. Tyrosine is   important  in brain function for alertness, focus,nervous communication.

The  adoption of protein substitutes diet or regulated amino acid diet  is very important because , all the needed amino acid are available , thus protein catabolisms  which may  trigger phenylalanine build up  from muscles and liver storage withdrawal   is prevented thus  stabilizing its blood concentration.