A couple is expecting their first child. Both parents are carriers for an autosomal recessive disorder. What is the probability that their child will be phenotypically unaffected by the disorder, assuming complete penetrance?

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D) 75%. When both parents are carriers (Aa x Aa), there is a 25% chance of an affected child (aa), a 50% chance of a carrier child (Aa), and a 25% chance of an unaffected, non-carrier child (AA). Therefore, 75% will be phenotypically unaffected.

A couple is expecting their first child. Both parents are carriers for an autosomal recessive disorder. What is the probability that their child will be phenotypically unaffected by the disorder, assuming complete penetrance?

✓ Correct Answer: Option D

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