The difference between normal and sickle hemoglobin at the DNA, RNA, and protein is that a sickle hemoglobin at the DNA is a result of a point mutation from one base. The RNA in a sickle hemoglobin changes from GAG to GUG, and the protein (amino acid) level changes from GLU to Val). Sickle cell is a genetic disorder, which is produced by a change in the nucleotide progression that codes for a protein. In this example, sickle cell is produced by one single nucleotide being changed for another (so, instead of the DNA being AATTGC, it would be AATAGC).