What is the main consequence of a point mutation?

A point mutation involves a change in a single nucleotide base pair in the DNA sequence. This alteration can lead to a change in the corresponding codon on the mRNA, resulting in the production of a protein that may have one different amino acid compared to the original protein. This type of mutation can affect the structure and function of the resulting protein, which is often the intended focus in genetics.

For instance, in a gene coding for a protein, if one nucleotide is changed—from adenine to guanine, for example—the codon may alter from coding for one specific amino acid to coding for another. This scenario is essential in processes like natural selection, protein function, and genetic diversity.

While point mutations can sometimes result in a loss of function, this is not universally the case since many point mutations may also have neutral or even beneficial effects. The deletion of an entire gene constitutes a different type of mutation, known as a deletion mutation, which is not the result of a single base change. Additionally, mutations associated with resistance to drugs often involve broader changes in DNA that go beyond a single point mutation. Thus, the impact of a point mutation primarily manifests as a change in a single amino acid within a protein.