Question

Mateo, an infant, is on a special diet as his parents are aware that he has a genetic disorder in which he cannot metabolize phenylalanine, an amino acid. Mateo's parents are also aware of the importance of this diet and that excess phenylalanine buildup in the infant will produce intellectual disability and hyperactivity. This genetic disorder results from a ______.

Answer 1

mutation in PAH gene

Step-by-step explanation:

A mutation in PAH gene leads to phenylketonuria which is an inborn error of metabolism. Metabolism of amino acid phenylalanine is reduced which leads to its build up in blood. It can lead to seizures, intellectual disability, mental disorder and behavioural problem. It is an autosomal recessive disease. PAH gene is mutated which leads to low level of phenylalanine hydroxylase enzyme. Phenylalanine is not broken down leading to its buildup and toxicity.

Treatment is done with supplements and with food having low levels of phenylalanine. If diagnosed early and a strict diet is maintained, patients can lead a normal life with average life span. Sometimes sapropterin dihydrochloride medication is also used.

Since Mateo can not metabolise phenylalanine, he suffers from phenylketonuria.

Answer 2

The correct answer is - mutation in autosomal recessive gene cause defect in the PAH gene.

Explanation:

Phenylketonuria is a genetic disorder that arises from the mutation in the autosomal gene which is recessive disorder. It causes a defect in the PAH gene in an individual which is essential to create a phenylalanine hydroxylase enzyme that helps in breaking the phenylalanine down.

The defect in the PAH gene breakdown of phenylalanine is disturbed and its buildup in the body takes place which is dangerous as it causes intellectual disability and hyperactivity.

Thus, the correct answer is - mutation in autosomal recessive gene cause defect in the PAH gene.