Point mutation is the exchange of a single nucleotide for another. It could be classified as: transition (change of a purine for another purine or a pyrimidine base for another pyrimidine); transversion (change of a purine base for a pyrimidine or a pyrimidine for a purine).
Also, Point mutation that occur within the protein coding region of a gene can be classified into different kinds, they are:
- Silent mutation
- Missense mutation
- Non-sense mutation
- Frameshift mutation - this is a kind of point mutation where a single nucleotide can be added or subtracted from the DNA sequence.
