Can you please explain the genotype of a sickle cell?

A>T mutation: A single point mutation in the dna (an "a" is mutated into a "t") leads to a glutamic acid being replaced by a valine in the hemoglobin protein. To have sickle cell disease, both copies of the gene encoding for hemoglobin have this mutation, leading to the disease.

Not sure.: There are several genotypes that we call sickle cell anemia. Usually, sickle cell anemia is same as homozygous sickle cell anemia (hbss). Other sickle cell genotypes are sickle beta-thalassemia (hbs-beta-thal), sc disease (hbsc), and less commonly hbsd. These genotypes all give sickle cell phenotypes.