Question

Genetic counseling is useful in predicting the probability of a child being born with a Mendelian inherited trait. Sickle cell anemia is caused by a recessive allele. A couple would like to know the chances of their child having sickle cell anemia. Parent #2 has the disease; parent #1 does not. Based on phenotype, parent #2 would have the genotype, ss. Parent #1 could be genotype, SS or Ss. Punnett Squares have been set up for crosses using both possible genotypes of parent #1. Should the couple be concerned that their child may have sickle cell disease? Why or why not?

Answer 1

6Ss, 2ss

The parents should be concerned, because the Punnett squares show that child may have sickle cell disease in $25\%$ .