Mateo, an Infant, Is on a Special Diet as His

Multiple Choice

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

A) dominant gene.
B) recessive gene.
C) complementary gene.
D) longevity gene.