Sickle Cell Anemia Case Study

To whom it may concern: This letter is to inform you about the genetic status of Aminata and Nelson and to help you advise them on their decision of whether or not to have a child. The probability that Nelson and Aminata’s child will have sickle cell anemia is a 1 in 20 chance. By calculating the probability that Nelson is a heterozygous carrier of the HbS gene (.67), then the probability that Aminata is also a heterozygous carrier of the HbS gene (0.30), and finally the probability that two heterozygous carrier parents will produce heterozygous recessive offspring with sickle cell anemia (0.25), I calculated the probability of Nelson and Aminata having a child with sickle cell anemia. When all three of these values are multiplied together, they yield the probability of Aminata and Nelson having a child with sickle cell anemia. Since (0.67) x (0.30) x (0.25) equals 0.05, this means that there is a 1/20 or 5% chance that the parents will have a child who is heterozygous for the HbS allele and thus inevitably develop sickle cell anemia. …show more content…
This has been shown to occur in very wet regions of Africa with lots of mosquitoes and the potential for contracting malaria. In these regions, the frequency of the HbS allele is very high due to the apparent advantage that carriers of the HbS allele appear to have for surviving encounters with the disease (Aidoo et al., 2002). Due to the principle of natural selection, this would allow more people who carry the HbS allele to survive and reproduce and thus increase the frequency of the HbS allele within the population. However, as the frequency of the HbS allele increases, so to does the risk that two HbS alleles will combine in some individuals and cause a condition known as sickle cell