Molecules of sickle-cell hemoglobin stick to one another ... often resulting in a frameshift One form of beta-thalassemia Deletion One or more nucleotides is "skipped" during replication or ...

as well as those with beta thalassemia. In sickle cell disease, a gene mutation causes the hemoglobin molecules in red blood cells to form a rigid chain. This causes the cells to stiffen into a ...