Question

Q.a female whose father had phenylketonuria marries normal man what are the chances of a son being diseased.

a.100%
b.50%
c 25%
d.0%

Answer 1

Answer:

a 100%...................

Answer 2

Phenylketonuria is an inborn error of metabolism is also inherited as the autosomal recessive trait.

Explanation:

• The answer is d) 0%
• The female is a carrier for phenylketonuria, as her father had it. She marries a normal man.
• As, it is autosomal recessive disease, therefore it can be transmitted from parents to the offspring when both male and female individuals are the carrier for the gene.
• Here only female is the carrier.
• Individuals having phenylketonuria, lack a liver enzyme called phenylalanine hydroxylase that converts the amino acid phenylalanine into tyrosine.
• The phenylalanine gets accumulated and it is converted into phenyl pyruvic acid and it's derivatives.
• In the brain, it gets accumulated that results in mental retardation.