Hemoglobin is the critical protein molecule that provides the shape of the red blood cell, which is a round shape with a small center. Sickle cell anemia is a blood condition produced by abnormal hemoglobin proteins present in the red blood cells, and they have sickle and crescent shapes. They are created as a result of sickle cell gene mutation. This mutation alters the amino acid sequence of normal hemoglobin, and sickle cell hemoglobin is also containing two alpha and two beta subunits. In normal hemoglobin, the 6th position of the amino acid chain in the beta chain is composed of glutamic acid. However, in sickle cell hemoglobin in the 6th position is taken up by different amino acids known as valine. Though it is a single amino acid variation, it is the cause of life-threatening anemia disease.