This is my rough draft
Sickle cell how it form and affect to human health
Sickle cell disease refers to a group of genetic disorders passed down a lineage and which are associated with a wide range of complications. Red blood cells typically live from 90 to 120 days, but sickle cells only survive for 10-20 days. The red blood cell disorders affect the abilities of the erythrocytes to transport adequate concentrations of oxygen to the respiring tissues (Pace et al., 2012). The C-shaped red blood cells increase the viscosity of the blood and may result in injuries to the endothelial surfaces. Besides, the clumping together of the sickle shaped red blood cells could block the blood vessels and trigger ischemic stroke in affected persons.
Sickle cell disease is the most common hereditary blood disorder in the US. It is estimated that 100,000 individuals are living with the disease in the country. Sickle cell disease affects roughly 1 in every 365 Black or African American babies born. Also, this disease affects approximately 1 in every 16,300 Hispanic-American babies born (CDC, 2020). Sickle cell disease is caused by a recessive point mutation affecting the beta-hemoglobin gene located on chromosome 11. This results in the production of defective hemoglobin, a protein critical in the transport of oxygen from the lungs to the respiring tissues throughout the body. While the red blood cells with the normal hemoglobin are smooth, the defective red blood cells with hemoglobin S are sickle-shaped and cannot move freely within the blood vessels. Instead, they stick to one another and form long rod-like structures while simultaneously causing injuries to the walls of the vessels. The defective hemoglobin is implicated in the stiffness and sickle-shaped appearance of the affected erythrocytes. These defective red blood cells can block the vessels and could also cause major damages to the vital organs.
In terms of the pathophysiology, inheritance of the two copies of the recessive genes result in the production of the defective sickle-shaped red blood cells. These cells have limited capacities to pack hemoglobin and transport oxygen to respiring tissues. Also, the sickle-shaped erythrocytes are more likely to clump together and block the blood vessels leading to sickling crisis and ischemic stroke. The various types of sickle cell disease include HbSS, HbSC, and HbS beta thalassemia (Chakravorty & Williams, 2015). The most common form of the disease, however, remains sickle cell anemia.
The severity of the disease and associated symptoms vary significantly from one individual to another. One of the most common complications of the condition is sickling crisis, a condition that refers to the group of acute conditions that occur in SCD patients. These include
the vaso-occlusive crisis, hemolytic crisis, aplastic crisis, and the splenic sequestration crisis (Wonkam et al., 2015). Vaso-occlusive crisis is characterized by the blockage of the blood vessels by the red blood cells. This could lead to ischemia, pain, and necrosis among other symptoms. On the other hand, aplastic crisis refers to the acute cases of anemia that are characterized by fast heart rate and pale appearance of the affected individuals. Hemolytic crisis is characterized by an accelerated drop in the levels of hemoglobin which is critical in the transport of the respiratory gases (CDC, 2016). Hemolytic crises are most often reported in persons with underlying G6PD deficiency.
The disease is autosomal recessive and is only expressed in individuals that have two copies of the recessive gene. Therefore, the risk of contracting the disease is highest among individuals with one of both sickling parents, and those with familial histories of the disease. Even in parents who may appear normal, the recessive trait may still be passed on to their offspring. Genetic screening could thus be considered as a tool to inform marriages and minimize the chances of the disease being passed on to the offspring (Aneke & Okocha, 2016).
The disease can be diagnosed through simple blood tests such as sickling test, and through newborn screening. Early diagnosis is vital due to the higher susceptibility of the affected children to other novel health problems. In the US, SCD diagnosis is part of the routine newborn screening. The tests focus on establishing the presence or absence of defective hemoglobin. Also, blood tests can be done in older children and adults suspected to have SCD.
Pace, B. S., Ofori-Acquah, S. F., & Peterson, K. R. (2012). Sickle Cell Disease: Genetics, Cellular and Molecular Mechanisms, and Therapies. Anemia, 2012. https://doi.org/10.1155/2012/143594
Chakravorty, S., & Williams, T. N. (2015). Sickle cell disease: A neglected chronic disease of increasing global health importance. Archives of Disease in Childhood, 100(1), 48–53. https://doi.org/10.1136/archdischild-2013-303773
Wonkam, A., Bitoungui, V. J. N., & Ngogang, J. (2015). Perspectives in Genetics and Sickle Cell Disease Prevention in Africa: Beyond the Preliminary Data from Cameroon. Public Health Genomics, 18(4), 237–241. https://doi.org/10.1159/000431020
Aneke, J., & Okocha, C. (2016). Sickle cell disease genetic counseling and testing: A review. Archives of Medicine and Health Sciences, 4(1), 50. https://doi.org/10.4103/2321-4848.183342
CDC. (2020, December 16). What is Sickle Cell Disease? Data & Statistics on Sickle Cell Disease. https://www.cdc.gov/ncbddd/sicklecell/data.html