Problem
Sickle cell is a recessive disorder. This means that the functional non-mutated allele (S) is dominant over the mutated allele associated with sickle cell disease (s).
You work with a woman named Lourdes. Lourdes does not have sickle cell anemia but has a full-blood brother with the disease. Neither of their parents has sickle cell anemia. What is the genotype of Lourdes' parents?