In which among the following disease the affected individual lacks an enzyme that converts phenylalanine into tyrosine ?

Phenylketonuria

The correct answer is option (3)- Phenylketonuria

Phenylketonuria: This inborn error of metabolism is  inherited as the autosomal recessive trait.

The affected individual lacks an enzyme that converts the amino acid phenylalanine into tyrosine. As a result of this phenylalanine is accumulated and converted into phenylpyruvic acid and other derivatives.Accumulation of these in brain results in mental retardation. These are also excreted through urine because of its poor absorption by kidney.