Frameshift mutation

A frameshift or frameshift or frameshift is a special type of mutation. There is a shift of the reading frame of genes on the DNA. The genetic information in DNA is organized in the form of base triplets or codons encoding this three bases of an amino acid. Now is a base of a gene in the context of a mutation lost ( deletion ) or added ( insertion), the reading frame of the following base triplets after the mutation changed.

As a result, the first codon of the mutated sequence has the original base sequence, the following codon change. Thus, other amino acids may be coded or it may cause a termination of translation, since a stop codon can be caused by the mutation. Although this change affects only a single base, the impact can be significant. Frameshifts caused among other things by intercalating substances.

Deletion

  • Original base sequence:
  • Deletion of one base: A ( first base in the third codon )

Insertion

  • Original base sequence:
  • Insertion of a base: T ( first base in the second codon )

Descriptive clarification

The following sentence is a good example to illustrate the effect of mutations on the reading frame:

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