What is the probability of am man and woman giving birth to a child who to is sickle cell like both of them?

If both parents are carriers of the sickle cell trait (genotype AS), there is a 25% chance that their child will inherit the sickle cell disease (genotype SS). Each parent has one normal hemoglobin allele (A) and one sickle cell allele (S), which means the possible combinations for their child are AA, AS, and SS. Therefore, the probability of the child being affected by sickle cell disease is 25%. If both parents have sickle cell disease (genotype SS), then all children will also be affected (100%).