Point mutation

mutation of a single gene

A point mutation is a single base substitution.[1] It is the smallest type of mutation possible.

Illustration of three types of point mutations.

In a point mutation, either:

  1. a single base nucleotide is changed for another nucleotide of the genetic material (normally DNA),[2] or
  2. a single base pair is inserted or deleted.[3]

A nonsense mutation is a point mutation in a DNA sequence that leads to an early stop codon.[4] This appears as a nonsense codon in the transcribed mRNA. Most of the time, the protein that is translated from this mRNA does not work.

References

change
  1. "What is a mutation?". University of Texas, El Passo. Archived from the original on December 3, 2016. Retrieved January 23, 2017.
  2. "Glossary: point mutation". Rosalind. Retrieved January 23, 2017.
  3. "How DNA changes affect phenotype". National Center for Biotechnology Information, U.S. National Library of Medicine. Retrieved January 23, 2017.
  4. Eldon D Enger; Frederick C Ross; David B Bailey, Concepts in Biology, 12th Edition (London: McGraw-Hill, 2007), p. 158