Several types of mutation are identified and described in the chapter. These include (1) promoter mutation, (2) splice site mutation, (3) missense mutation, (4) frameshift mutation, and 5) nonsense mutation. Match the following mutation descriptions with the type(s) of mutations listed above. More than one mutation type might match a description.

A mutation that changes several amino acids in a protein and results in a protein that is shorter than the wild-type product.

Key Concepts

Frameshift Mutation

A frameshift mutation occurs when nucleotides are inserted or deleted from the DNA sequence, altering the reading frame of the gene. This change can lead to the production of a completely different protein, often resulting in a truncated protein due to premature stop codons. Such mutations can significantly impact the function of the protein, making them critical in genetic disorders.

Nonsense Mutation

A nonsense mutation is a specific type of mutation that converts a codon encoding an amino acid into a stop codon. This premature termination of translation results in a shorter, often nonfunctional protein. Nonsense mutations can have severe consequences, particularly if they occur in essential genes, leading to various genetic diseases.

Missense Mutation

A missense mutation is a point mutation that results in the substitution of one amino acid for another in a protein. Depending on the nature of the amino acid change, this can affect the protein's function, stability, or interaction with other molecules. While some missense mutations may have little effect, others can lead to significant changes in phenotype or disease.