Name the kind of disease or disorder that is likely to occur in humans if there is a mutation in the gene that codes for an enzyme phenylalanine hydroxylase:

Options

A. Phenylketonuria
B. Huntington's disease
C. Turner's syndrome
D. Sickle cell anaemia

Answer

A

Explanation

Phenylketonuria is an inborn error of metabolism that is inherited as an autosomal recessive trait.
The disease is characterized by the absence of an enzyme (phenylalanine hydroxylase) in affected individual that converts the amino acid phenylalanine into tyrosine in the liver.
This results in the accumulation of phenylalanine which gets converted into phenylpyruvic acid and other derivatives. These accumulate in the brain and results in mental retardation and also due to its poor absorption by kidney, these are also excreted through urine.