A silent mutation occurs when a DNA message changes but the message still codes for the same amino acid and produces the correct protein. This is different from a regular DNA mutation, in which the amino acid is either changed or deleted, explains the U.S. Food and Drug Administration.
Silent mutations, also called synonymous mutations, have long been thought to be a benign process because no changes occur in the amino acid sequence, resulting in the production of the normal protein. Recent studies, however, show that even though the protein remains the same, silent mutations can cause changes in the shape of mRNA, resulting in the interruption of its interaction with ribosomes. This interruption can cause a decrease in the production of the protein as well as a change in its shape, causing it to work improperly, states the FDA.
Scientists are now able to use the presence of certain silent mutations to predict the susceptibility of some patients to particular diseases and treatment outcomes. For example, one type of silent mutation places people at a higher risk for the development of cardiomyopathy, which is a condition in which the heart does not contract normally, while another silent mutation has a correlation with the survivability of children with acute myeloid leukemia.