A person with a phenotype of HbSS has sickle cell disease, a person with a phenotype of HbAS allele carries the sickle cell trait. A person with a phenotype of HbAA doesn’t have sickle cell disease and doesn’t carry the trait. The Punnett square shows the phenotype of two people carrying the sickle cell trait. What are the chances that their offspring will have sickle cell anemia?
The Punnett square in the image shows the resulting progeny after a cross between the two individuals of the genotype, HbAS, who are carrying the sickle cell gene. The probability of offspring getting sickle cell disease turns out to be, 25%.
