Question

In severe Hunter syndrome, lack of the enzyme iduronate sulfate sulfatase leads to buildup of certain carbohydrates swelling the liver, spleen, and heart. In mild cases, deafness may be the only symptom. Intellect is usually normal, and life span can be normal. Hunter syndrome is X-linked recessive. A man with mild Hunter syndrome has a child with a woman who is a carrier.

a.	What is the probability that a son inherits Hunter syndrome?
b.	What is the chance that a daughter inherits Hunter syndrome?
c.	What is the chance that a daughter is a carrier?

Answer 1

let the genotype of mother be (carrier) XX^h and genotype of father be X^hY (diseased).

a. Chances of having a son with the disease will be 1/4 of the overall children; or 1/2 of the sons.

b. Chances of having a daughter with the disease will be 1/4 of the overall children; or 1/2 of the daughters.

c. Chances of having a heterozygous daughter will be 1/4 of the overall children; or 1/2 of the daughters.