zi
Forum Newbie
Topics: 2
Posts: 9
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A married couple is screened to assess the risk of Tay Sachs disease in their children. The activities of hexosaminidase A in the sera of Mother and Father are 45% and 55% respectively, of the reference value. The couple has one child. What is the probability of the child possessing one or more alleles of the Tay-Sachs mutation?
A) 0.0
B) 0.25
C) 0.5
D) 0.75
E) 1.0
Please provide answer with explanation. Thank you. :wink:
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| Ahab
Forum Elite
Topics: 9
Posts: 228
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D. 0.75
Both enzyme activities are in the 50% range, meaning that each parent has one functional gene expressing hexosaminidase A
Each parent has one defective gene.
Probability of Parents having a normal offspring with both copies of hA 1/4.
Probality of parents having offspring with at least one gene defective =1-1/4= 0.75
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