Types Of Point Mutations

Evaluating the Varied Types of Point Mutations – Important Differences and Similarities

When considering the damage or advantages caused by point mutations, it is essential to evaluate the different types of point mutations that can occur. Whether you’re considering genetic experiments, or looking to understand how mutations occur naturally or as a result of environmental changes, looking at possible types of mutations can help a great deal. It will not only help evaluate the way certain organisms respond to external stimulation, but also shed some light on what the most damaging mutations are.

How Do Point Mutation Types Work?

When DNA is transcribed by messenger RNA, it’s on its way to generating proteins, the building blocks of life. As the DNA is “read” by the RNA three bases at a time, it also matches its complementary bases to it to create what is known as codons. Each codon codes for a different amino acid, and chains of these amino acids generate proteins. Now, should the DNA be affected by different types of point mutations, the information read by the RNA is no longer the same. As a result, understanding the specific type of mutation that happens is extremely essential, if we want to know exactly how the protein was affected and what the repercussions might be.

Substitution Mutations

One of the main types of point mutations that are possible are substitution mutations. These can involve one of three varieties of mutations that have to do with one base pair being substituted with another. An example would be when a nucleotide that contains cytosine is substituted by accident with one containing guanine. The most common type of substitution mutation is the missense mutation, in which the substitution leads to a different codon being formed than the original. If the amino acid formed has similar properties to the original, then we’re talking about a conservative mutation. Otherwise, the mutation is non-conservative, and can lead to severe destabilization in the chain of codons. Silent and nonsense mutations can also occur, but these are more specific and, therefore, less common types of substitution mutations. They lead to either a stop codon (nonsense mutation) or a near identical codon to the original being formed.

Insertion vs. Deletion Mutations

If an extra base pair is added to a sequence of base pairs, then the mutation that occurs is an insertion mutation. Deletion mutations, on the other hand, are opposite types of point mutations. They involve the removal of a base pair. Both of these mutations lead to the creation of the most dangerous type of point mutations of them all: the frameshift mutation.

Why It’s Important to Understand Types of Mutations

Knowing which types of mutations have occurred in an organism can account for the various disorders or adaptations that have happened since the change. In some cases, these changes are benign or beneficial, however, they can also be negative or only temporarily neutral. Figuring out which types of point mutations you are dealing with can determine the next course of action to help fend off certain genetic unbalances, repair the protein encoding and even prevent the onset of a certain disease before it even happens.