Editing Missense mutation (section)

=== Sickle Cell ===
[[File:Sickle cell anemia.jpg|thumb|(1) Normal red blood cells and (2) sickled-cell red blood cells]][[Sickle cell disease|Sickle-cell disease]] changes the shape of red blood cells from round to sickle shaped.<ref name=":9">{{Cite journal |last1=Esoh |first1=Kevin |last2=Wonkam |first2=Ambroise |date=2021-03-01 |title=Evolutionary history of sickle-cell mutation: implications for global genetic medicine |url=https://academic.oup.com/hmg/article/30/R1/R119/6103809 |journal=Human Molecular Genetics |volume=30 |issue=R1 |pages=R119–R128 |doi=10.1093/hmg/ddab004 |issn=0964-6906 |pmc=8117455 |pmid=33461216}}</ref> In the most common variant of sickle-cell disease, the 20th nucleotide of the gene for the [[beta chain]] of [[hemoglobin]] is altered from the [[codon]] GAG to GTG.<ref name=":9" /> Thus, the 6th amino acid, [[glutamic acid]], is substituted by [[valine]]—notated as an "E6V" or a "Glu6Val" mutation—which causes the protein to be sufficiently altered with a sickle-cell phenotype.<ref>{{cite web |title=141900 Hemoglobin—Beta Locus; HBB: .0243 Hemoglobin S. Sickle Cell Anemia, included. Malaria, Resistance to, included. HBB, GLU6VAL — 141900.0243 |url=http://omim.org/entry/141900#141900Variants0243 |publisher=[[Mendelian Inheritance in Man|Online 'Mendelian Inheritance in Man']] (OMIM)}}</ref> The affected cells cause issues in the bloodstream as they can become sticky due to their improper ion transport leading to them being susceptible to water loss.<ref name=":1">{{Cite journal |last1=Parker |first1=J. C. |last2=Orringer |first2=E. P. |date=1990-04-27 |title=Sickle Cell Disease. Charles F. Whrrren and John F. Bertles, Eds. New York Academy of Sciences, New York, 1989. xiv, 477 pp., illus. $119. Annals of the New York Academy of Sciences, vol. 565. From a conference, Bethesda, MD, April 1988 |url=https://doi.org/10.1126/science.248.4954.502 |journal=Science |volume=248 |issue=4954 |pages=502 |doi=10.1126/science.248.4954.502 |pmid=17815604 |issn=0036-8075|url-access=subscription }}</ref> This can cause a buildup of blood cells that obstructs blood flow to any organ in the body.<ref name=":1" />