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

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.