Point mutation

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

In a point mutation, either:
a single base nucleotide is changed for another nucleotide of the genetic material (normally DNA), or
a single base pair is inserted or deleted.

A nonsense mutation is a point mutation in a DNA sequence that leads to an early stop codon.Eldon D Enger; Frederick C Ross; David B Bailey, Concepts in Biology, 12th Edition (London: McGraw-Hill, 2007), p. 158 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 

Category:Genetics
Category:DNA