Point Mutation

A point mutation is a simple change in one base of the gene sequence.There are four main types of point mutation:

Missense mutation: changes of codons that cause substitution of one aa for another.

Nonsense mutation: converts an amino acid into a stop codon, UGA, UAA or UAG

Transition mutations:Purine replaces other purine (AT®GT) or pyrimidine replaces other pyrimidine (CT ® TT)Transversion mutations:Purine is replaced by a pyrimidine or vice versa, e.g. AG ® TG or AC