Substitution mutation

Substitution mutation is a type of mutation that involves the replacement of one nucleotide base with another in the DNA sequence. This type of mutation can lead to the production of a different amino acid during the process of protein synthesis, potentially altering the function of the resulting protein.

Overview

In a substitution mutation, a single nucleotide base is replaced by another. These mutations can occur in any cell of the body and at any point in life. They can be caused by a variety of factors, including exposure to certain chemicals or radiation, errors during DNA replication, or inherited from a parent.

Types of Substitution Mutations

There are two main types of substitution mutations: transitions and transversions.

Transitions

Transitions are the most common type of substitution mutation. They involve the substitution of a purine for a purine (A ↔ G) or a pyrimidine for a pyrimidine (C ↔ T).

Transversions

Transversions are less common than transitions. They involve the substitution of a purine for a pyrimidine or vice versa (A ↔ C, A ↔ T, G ↔ C, G ↔ T).

Effects of Substitution Mutations

The effects of substitution mutations can vary widely, depending on where in the DNA sequence they occur and what type of substitution it is. Some substitution mutations are silent, meaning they do not change the amino acid sequence of the protein. Others can result in a missense or nonsense mutation, leading to a change in the protein sequence or a premature stop codon, respectively.

See Also

• Point mutation
• Frameshift mutation
• Genetic variation
• Molecular genetics