Keywords: Sickle Cell Anemia.jpg en A Hemoglobin is made up of 4 chains 2 α and 2 β In Sickle Cell Anemia a missense mutation causes the amino acid glutamic acid Glu to be replaced by valine Val in the β chains of HbA resulting in the abnormal HbS B Under certain conditions such as low oxygen levels red blood cells with HbS distort into sickled shapes C These sickle cells can block small vessels producing microvascular occlusions which may cause necrosis death of the tissue 2013-04-25 23 52 34 http //www ncbi nlm nih gov/books/NBK22238/ National Center for Biotechnology Information US PD-USGov Uploaded with UploadWizard Sickle-cell anemia |