Frameshift mutations are among the most deleterious changes to the coding sequence of a protein. ... This can even overwhelm the translation machinery of the cell, result in a large number of misfolded proteins that could eventually lead to large-scale impairment of all functions of even cell death.

Is a frameshift mutation lethal?

As a result, the formation of a large number of misfolded proteins could occur and that could be lethal for a cell. However, the altered protein could also be beneficial and could provide protection as observed in HIV patients due to frameshift mutation in the chemokine receptor gene (CCR5).

Can frameshift mutations be beneficial?

Frameshift mutations can also be beneficial. Frameshifting may also occur during protein translation, producing different proteins from overlapping open reading frames, such as the gag-pol-env retroviral proteins.