Introduction

The first description of the sickle cell disease was introduced to the world in 1910. ³In 1922, after the discovery of three more cases, the disease was named "sickle cell anemia." Although cell anemia affects mostly Africans it was not recorded in African literature until 1870, Sickle cell anemia is a genetic disorder which is usually inherited through generations; it is a genetic mutation of the allele for hemoglobin production. It cannot be "caught" and can only be inherited.  

This disease is an example of co-dominance inheritance. The allele for sickle cell anemia is Hb^S and for healthy red blood cells the allele is Hb^A. Both parents must be either carriers or affected by sickle cell anemia to have children that inherit the disease. A carrier of the sickle cell trait has both sickle shape red blood cells and healthy red blood cells.

 The allele for this disease leads red blood cells to become a sickle shaped red blood cell. These mutated red blood cells do not transport oxygen effectively since it is difficult for them to pass through the small blood vessels and capillaries. These conditions lead to blockages and tissue damage in the body.

Round are healthy red blood cells and C-shaped are sickle red blood cells. Image taken from http://img.ehowcdn.com/article-page-main/ehow/images/a04/ue/h3/sickle-cell-anemia-treatments-800x800.jpg

Causes

Sickle cell anemia is caused by a mutation in the allele that is responsible for hemoglobin. It is abnormal hemoglobin known as Hemoglobin S. ²This trait can only be inherited therefore, if two heterozygous parents for this trait were to mate, there is a possibility that the child will have sickle cell anemia.

Hemoglobin is a specialized iron-containing protein found in red blood cells. His protein binds with oxygen to help in the process of gas exchange and it also binds with a little carbon dioxide when receiving carbon dioxide from body tissue. ⁶Mutated hemoglobin causes the shape of red blood cells to deform into a sickle shape. Since the sickle cell is less flexible and stiffer, it makes traveling through the red blood vessels extremely difficult and it breaks into pieces that disrupt healthy blood flow. The sickle shape slows down the speed of the red blood cells. All together, the sickle shaped cells start clogging vessels and result in organs being deprived of oxygen and having an abundance of carbon dioxide.

Causes of the sickle cell disease

Diagnosis and Treatment

With the help of our modern technology, sickle cell anemia can be easily found the day you are born. With the use of genetic screening, newborn babies are checked whether they have the sickle cell disease or not. The results do not come immediately, once the results are determined, the final report is sent to the family doctor. If the newborn is diagnosed with sickle cell anemia the family doctor will refer the parents to take the child to a hematologist, a doctor who specializes in blood disorders.

⁸For parents who want to know whether their unborn baby carries the disease there is an option they may take to find out. Doctors can sample amniotic fluid (fluid that surrounds the unborn baby in the mother's womb) to search for the sickle cell trait.

When dealing with adults, a blood test can check for hemoglobin S. A blood sample is taken and screened for hemoglobin S. If the result for the screening test is negative, there is no sickle cell gene present in the DNA. If the result of the test is positive, more tests will be done to determine whether there are one or two alleles present for the sickle cell gene. Many tests are done before diagnosis to ensure that there are no mistakes in the process, this avoids false accusations. ⁷Once diagnosed with sickle cell anemia, the patient is sent to a genetic counsellor who is an expert in the disease. Treatment will begin from that point onwards.

 There are ways of reducing the symptoms of sickle cell anemia but it is impossible to completely cure the disease. To reduce symptoms, doctors prescribe patients with vaccines, antibiotics, folic acid supplements and pain killers. Patients are required to do constant check-ups to check their red blood cell count and oxygen levels. In very severe cases, doctors may request blood transfusions.  In a blood transfusion, red blood cells are given to the patient from donated blood. This increases the number of red blood cells in the patient's body, which helps ease anemia and reduces the risks of strokes. The down side to regular blood transfusions is that there is a build up of iron in the patient's body which can damage the heart, liver, and other organs. To solve this issue, patients who receive regular blood transfusions must take supplements to reduce their iron levels.

 Cures for sickle cell anemia are still being researched and by far the only treatment discovered is a bone marrow transplant. Bone marrow transplant requires the affected bone marrow to be replaced by a donor's healthy bone marrow. After the replacement, the patient takes many drugs to help prevent the donated stem cells from rejecting the transplant. The down side to bone marrow transplant is that it is expensive, ranging from $15,000 - $50,000⁴. Also there are many risks towards performing the surgery like internal bleeding in the lungs, rejection of the transplant by the stem cells, and decrease in immunity. Another factor that makes this transplant difficult is searching for a donor. Therefore, more research is being done to find a safer, more reliable cure to sickle cell anemia.

The bone marrow that must be replaced in a bone marrow transplant. Image taken from http://www.nlm.nih.gov/medlineplus/images/longbone.jpg

Symptoms

When diagnosed with sickle cell anemia, as an infant, the symptoms are not seen immediately. Usually the symptoms do not occur until after 4 months⁶. Patients that have sickle cell anemia experience chronic pain that is very severe. This pain may last from hours to days and even continue on for weeks.

Blood clotting because of sickle shaped red blood cells. Image taken from https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEieH5VQXiYVOTwfZlkYHw5Gqykiy7N_AlOwtdBJ1lyyM8KQcQJhqfd1fjA1-iIDw4R1ReoeFF4XRH_ARk2bR_nCzUunkHaMSJHOf2jOPdUuj_PQJeerI_ln2ekaFEcV19RO0rQmXbQzXFHo/s1600/Sickle_cell+2.png

Common symptoms of this disease are extreme pains, hand-foot syndrome, frequent infections, pale skin, and any signs or symptoms of strokes. The extreme pains are caused by sickle shaped blood cells that clog in parts of your body like your chest or abdomen, this pain can also happen in your bones. Hand-foot syndrome is when your hands and feet swell caused by the blockage of blood flow in your hands and feet. This is mostly noticeable in infants. Frequent infections are a symptom because the sickle cells may possibly damage your spleen which fights infections in your body. Once the spleen is damaged you body becomes less immune towards infections. Pale skin is caused by a decrease in red blood cells, this is common for patients diagnosed with sickle cell anemia because the sickle cell only lasts for 10 to 20 days where as a healthy blood cell lasts for 120 days¹. This results in a constant shortage of red blood cells which can potentially be life threatening. Symptoms of strokes may occur because of insufficient blood flow throughout the body.

Symptoms shown in an infant. Image taken from http://wikieducator.org/images/6/60/Sickelcells2.jpg

The Sickle Cell Trait

Sickle Cell Anemia

Inheritance

Inheritance patterns of the sickle cell trait. Image taken from http://www.daviddarling.info/images/inheriting_sickle_cell_genes.jpg

Lifestyle

An individual who is diagnosed with sickle cell anemia must make many changes to their lifestyle. A patient must visit their doctor daily to receive their red blood cell count and check up on their lungs. On top of that, patients must take daily medication including folic acid supplements³. To maintain a healthy lifestyle they must choose a healthy diet that provides them with the vitamins they need. To avoid pain they must ensure they avoid dehydration, extreme temperatures, and stressful situations.  Their lifestyle must include regular exercise to ensure a healthy body, and when on trips they must fly on airplanes with pressurized cabins and plan ahead when travelling to high-altitude areas. These are crucial rules you must follow to ensure your safety⁵.

A healthy lifestyle is mixed with a healthy diet and atleast 30 minutes of excercise everyday. Image taken from https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgH-SG9B1Aj1Oz7xkHW-h4NCpVKEdq01XJkEYlAkSuKC_6NylGBbiqvBWy2VAY-Ioli_esaIJguZIvGXFz4uAgEGtuOzgqCRZ5eaOXRhyphenhyphenc0GVNgUJYT_N0kRz8vp2s5MhBfh5K60BcyiJs/s1600/healthy-lifestyle.jpg

Works Cited

¹About Sickle Cell Disease. (n.d.). William E. Proudford Sickle Cell Fund - Change is Coming. Retrieved November 3, 2011, from http://www.wepsicklecell.org/about/

²Chan, M. (n.d.). Genes and Human Disease. World Health Organization. Retrieved November 4, 2011, from www.who.int/genomics/public/geneticdiseases/en/index2.html#SCA

³Duff, S. (n.d.). Sickle Cell History. Innvista Home. Retrieved November 6, 2011, from http://www.innvista.com/health/ailments/anemias/sickhist.htm

⁴Jacobs, M. (n.d.). Cost of Bone Marrow Transplant. National Bone Marrow Transplant Link. Retrieved November 6, 2011, from http://www.nbmtlink.org/resources_support/rg/rg_costs.htm

⁵Foundation for Medical Education and Research. (n.d.). Sickle cell anemia. Mayo Clinic. Retrieved November 5, 2011, from http://www.mayoclinic.com/health/sickle-cell-anemia/DS00324

⁶Mukerji, I. (n.d.). Basics of Sickle Cell. About Sickle Cells. Retrieved November 6, 2011, from http://www.sicklecellinfo.net/basics_of_sickle_cell.htm

⁷Peterson, J. M. (2009). Understanding Sickle Cells. Sickle cell anemia (pp. 15-24). New York: Rosen Pub.

⁸Health. (n.d.). Sickle cell anemia. National Center for Biotechnology Information. Retrieved November 3, 2011, from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001554/