Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

Phenylketonuria is an autosomal recessive disorder. 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 the kidney.