The kind of mutation that occurs when a nucleotide is added or deleted is called a frameshift mutation. This type of mutation alters the reading frame of the genetic sequence, potentially leading to significant changes in the resulting protein. Depending on the position of the addition or deletion, frameshift mutations can have severe effects, including the production of nonfunctional proteins or early stop codons. These mutations play a critical role in genetic diversity as well as in various genetic disorders and diseases.