Question

If a couple with Sickle cell disease genotypes Ss and Ss mate and have one child with the disease, what is the chance the next child has the disease as well?

a) 0.5
b) 0.25
c) 0
d) 1

Answer 1

The chance that the next child of a couple, both with the Ss genotype for sickle cell disease, will also have the disease is 25%.

Step-by-step explanation:

The subject of the question is the inheritance of sickle cell disease, which is an autosomal recessive genetic condition. If both parents have the Ss genotype, each parent carries one sickle cell gene (S) and one normal gene (s). This means that for each child they have, there is a 25% chance of inheriting two sickle cell genes (SS), a 50% chance of inheriting one sickle cell gene and one normal gene (Ss), and a 25% chance of inheriting two normal genes (ss). Therefore, the chance that the next child will have sickle cell disease (SS) is 25%.