What Is a Point Mutation and Why Should You Know About It?
What is a point mutation and how is it relevant when it comes to the specifics of genetic manipulation through artificial means? Questions such as this one are at the core of genetic research, and they are extremely important in order for a clear understanding of mutations to be possible. Point mutations are typically known to be caused during DNA replication, and are thus a product of other genetic processes. They can be random and even quite dangerous in some cases.
What Are Point Mutations All About?
So what is a point mutation, and why is it important? Point mutations are the name given to genetic mutations which involve the change of a single nucleotide base. The base pairs can either be deleted or added to the organism’s genetic code through a variety of means. Some might involve DNA replication, while others have to do with the consequence of radiation – such as UV or X-rays. The end result and its consequences isn’t always fully predictable, although new methods for predicting point mutations have improved in recent years. They can range between synonymous mutations (which are typically benign) to the more dangerous frameshift mutations.
Other Types of Point Mutations
When considering just what is a point mutation, it’s also important to note that there are two other types of point mutations depending on whether there is a purine or pyrimidine base. The latter is known as a transition mutation, and the former is commonly named a transversion mutation. An example of a transition mutation is a GC base replacing a naturally occurring AT base pair. When it comes to transversion mutations, the idea is that a pyrimidine base is substituted by a purine base. In most cases, that translates as a TA or CG pair replacing a wild type AT pair.
The Frameshift Mutation
What is a point mutation, if not a problem to be solved? And the worse type of problem that can result is a frameshift mutation. Frameshift mutations can occur when the deletion or addition of one or more DNA base pairs leads to an alteration in a protein-coding gene sequence known as the reading frame. The reading frame is known to start with AUG and end with a termination codon. Now, if a nucleotide is either subtracted or added from this sequence, the result will be the shifting of all the downstream codons. The end result is a protein with one section describing a natural amino-acid and the other showing a meaningless series of nucleotides that can cause severe damage to the organism.
Examples of Diseases Caused by Point Mutations
If multiple tumor suppressors are affected by point mutations, the result is a form of cancer. A defect in the CFTR gene leads to cystic fibrosis. Similarly, a series of other very serious diseases are linked to point mutations as well. Some examples also include color blindness, neurofibromatosis, Tay–Sachs disease and some forms of anemia. If you ask what is a point mutation, most scientists will give you the scientific version of the explanation; but once they mention any of these disorders, it will be easy to understand the extent of the damage caused by point mutations, even in laymen terms.