gen-briefly-explain-a-frameshift-mutation-and-one-common-misconc-a94a

Briefly explain a frameshift mutation and one common misconception about it.

# Frameshift Mutation **What it is:** A frameshift mutation occurs when nucleotides are inserted into or deleted from DNA in numbers that aren't multiples of three. Since codons are read in groups of three bases, this shifts the entire "reading frame" downstream of the mutation, typically changing every amino acid that follows and usually producing a nonfunctional protein. **Common misconception:** Many people think frameshift mutations only affect a small, localized region of the protein. In reality, frameshift mutations affect **all codons downstream** from the point of mutation, not just the immediate area. This typically has devastating effects on protein function, often more severe than point mutations, because the entire C-terminal portion of the protein is altered and a premature stop codon is usually encountered.