If both parents are carriers for thalassemia, which is an autosomal recessive disorder, what are the

Question

If both parents are carriers for thalassemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?

Accepted Answer

Sol.(b) [Key Concept: Autosomal Recessive — Carrier × Carrier] Thalassemia is autosomal recessive. Both carrier parents: Tt × Tt → 1/4 TT (normal) : 2/4 Tt (carrier, unaffected) : 1/4 tt (affected with thalassemia). The chance of an affected child = 25% per pregnancy. The 50% risk applies to the probability of being a carrier (not affected); 100% would require both parents to be affected (tt × tt). Answer: 25% (b).

Question

Options

Solution

More Principle of Inheritance and Variation Questions