Gattaca in Africa: The Unique Qualities of Sickle Cell Anemia

Sickle cell anemia (homozygous Hb SS) constitutes 60-70% of sickle cell disease in the United States (Bender et. al, 2009) affecting 90,000 -100,000 individuals (CDC, 2010) and is a fascinating example of the dynamic nature of genetic distribution, adaptation, and disorders. The term sickle cell disease encompasses a group of symptomatic disorders associated with mutations in the HBB gene (Bender et. al., 2009). The disease is defined by the presence of hemoglobin S which is a result of a point mutation in the HBB gene in which the sixth amino acid in the hemoglobin chain is changed from glutamic acid to valine. Sickle cell prevalence is also a result of natural selection in regions of endemic malaria. This condition is attributed with high survival rates for those infected with acute malaria and depicts how a genetic disorder can gain momentum.

Sickle cell anemia is a debilitating disease characterized by intermittent vaso-occlusive events and chronic hemolytic anemia. Common symptoms include attacks of acute and chronic abdominal pain, bone pain, breathlessness, delayed growth and puberty, fatigue, fever, rapid heart rate, ulcers, and jaundice. Current treatment consists of symptom management as the condition is chronic and life-threatening and may include folic acid supplementation to encourage red blood cell production, pain medication during crises, and routine blood transfusions. Bone marrow or stem cell transplants are considered risky, yet viable options to cure the disease.

Currently, transfusions are readily utilized to treat sickle cell patients in order to improve blood flow by reducing the proportion of red cells capable of forming the sickle hemoglobin polymer (Raghypathy, 2010). However, a major and unavoidable complication of transfusions in sickle cell disease is iron overload. Iron overload can damage organs and cause other severe symptoms. The risks associated with such treatment are not easily quantified as there is no national database for sickle cell anemia (CDC, 2010). Prevalence rates, health outcomes, and impact on quality of life are not documented. Although every newborn is screened for sickle cell anemia, a national registry has not been established. From a public health perspective the establishment of such a center and service would enable additional documentation and dissemination of information such as the risks associated with iron overload. Surveillance is a key public health tool that allows health professionals to monitor and address health issues, sickle cell anemia should not be immune to such ongoing examination.


References

Bender, MA, Hobbs, W. (2009) Sickle Cell Anemia, Gene Reviews.

Centers for Disease Control and Prevention. Sickle Cell Disease. Retrieved on April 6, 2011 from www.cdc.gov/ncbddd/blooddisorders/documents/BBV_PNV_C0_1159_Sickle_Cell_R1mtr.pdf.

Raghupathy, R., Manwani, D., Little, J. (2010) Iron Overload in Sickle Cell Disease. Adv. Hematol. 272940. doi: 10.1155/2010/272940