Sickle Cell Disease (DNA and RNA)
Oct 29, 2020
I recently wrote this article for a Uni assigment giving me an understanding of the DNA and RNA process with mutations that can occur from genitics, this disease is not only very crippily but can reduce the life span of the individual by twenty to fourty percent.
Sickle cell disease is a blood disorder where the red blood cell takes the shape of a sickle which makes it easier to be destroyed leading to anemia the major cause of this is a defect in the hemoglobin causing a mutation their red blood cells continually deforms and squeezes through narrow capillaries the sickle shape and modification are determined by its membrane skeleton this red blood cell mutation has been associated with many other diseases including sepsis, malaria, heavy metal exposure, cardiovascular disease and neurological disorders Alapan 2016
The hemoglobin is made from 4 peptide chains bonded to a heme group with different combinations of chain these mutations are from the HBB gene these genes can also cause a sickle trait gene which does not cause health problems unless caused to extreme conditions, this mutation from the gene is a non-conservative missense mutation that occurs in the six amino acids of beta-globin being a valine instead of a glutamic acid the new hydrophobic acid has different properties than the one it replaced which is hydrophilic.
deoxygenated it changes its shape. It joins a chain of other HBS this process is acidosis- sickling decreasing the hemoglobin for oxygen and the hemoglobin dumping the oxygen from the low vessels, these repeated occurrences lead to the weakening of the cell membrane leading to premature destruction of the cells (intravascular hemolysis) leading to a deficiency in the RBC and loss of hemoglobin which is the major causes of anemia, once the hemoglobin starts to spill out it is recycled by haptoglobin transferred into bilirubin which can then lead to scleral icterus, jaundice, gallstones. Osmosis 2020
Once this genetic mutation has occurred, and the sickle cells start to clog capillaries affecting the person’s blood supply to be cut off to various tissues and muscles including the heart and brain there is major physical outy comes such as excessive pain, liver damage or even heart attack. Clancy 2018
The mutation occurs for reasons including unequal crossing over during meiosis; These focus points are the outcome of the DNA sequence itself being more available to mutagens that repeat the sequence just like the trinucleotide repeats, along with the nucleotides that are repeated three times in the chain which can alternate due to the polymerase slips in the DNA strand, the insertion and deletion of a single base cause these mutation and entire proteins are altered, codons are ribosomes which are usually in groups of three if they are not they can throw off the reading frame for the protein. Clancy 2008
There is also a natural error rate that can cause mutation in the process of the DNA replication the DNA repair machinery halts cell division of the wrongly placed nucleotide before mismatching the strand if the mistake is not caught the mutation will occur in the cell this will to putting organisms at risk of disease Clancy 2008
References
Yunus Alapan, Ceonne Kim, Anima Adhikari, Kayla E Gray, Evren Gurkan-Cavusoglu, Jane A little, Umut A Gurkan 2016, Sickle cell disease biochip: a functional red blood cell adhesion assay for monitoring sickle cell disease, science direct, page 74-91, viewed 27th October 2020,
https://www.sciencedirect.com/science/article/pii/S1931524416001006
Suzanne Clancy 2008, Genetic Mutations, Scitable, viewed 29th October 2020,
https://www.nature.com/scitable/topicpage/genetic-mutation-441/
Osmosis 2020, Sickle cell anemia, Video, Viewed 27th October 2020,
