Question

Phenylketonuria is an ______ disorder.

• A. autosomal recessive
• B. autosomal dominant
• C. X - linked recessive
• D. X - linked dominant

Answer 1

The correct option is A autosomal recessive

Phenylketonuria or PKU is a Mendelian autosomal recessive disorder which is also an inborn error of metabolism. Patients lack the enzyme phenylalanine hydroxylase which converts phenylalanine into tyrosine. This eventually results in mental retardation.