subject: The Gene Mutations And Your Health [print this page] Gene mutations can occur in the germ cells such as the egg or the sperm. Mutations can also be acquired in the later part of a person's life. Depending on the severity of the mutations, it can end an embryo's life during its early stages of development. The mutation in the gene can be a basis for developing genetic diseases as the genes rely on the proteins for the body to function properly. If instructions on producing proteins are changed in genes, the mutation occurs. The mutations in genes become permanent and passed on to the next generation.
However, not all gene mutations have a negative impact on a person's health and development. Rather, only a small percentage of gene mutations result to genetic disorders. Most of gene mutations do not have any effect on development and health condition of individuals. As an example, the mutations that change a gene's DNA base sequence do not modify the function of the protein produced by the gene.
Generally, the mutations on genes causing a genetic disorder are repaired by some specific enzymes before the gene makes protein. Every cell has several pathways by which the enzymes recognize and repair errors in the DNA. As the ways for mutating and damaging the DNA are manifolds, the process of DNA repair makes a very important measure of protecting the body from diseases.
A small percentage of gene mutations can even have positive effect on the body. This is when the mutations result to new versions of proteins capable of helping an organism and its future generations to better adapt to the changes in the environment. A good example of this premise is a beneficial mutation resulting to a protein that guards the organism from a new strain of bacteria.
The gene mutation can have different impact on the health, relative to where the mutation occurs and whether it changes the function of essential proteins. There are 7 types of gene mutations, namely missense, nonsense, insertion, deletion, duplication, frameshift, and repeat expansion.
In Missense mutation, the type of change is a mutation in one DNA base pair resulting in substitution of one amino acid for another in the protein produced by a gene.
Nonsense mutation also occurs in one DNA base pair. However, instead of making another amino acid as a substitute, the mutated DNA sequence prematurely informs the cell to stop making a protein, resulting to a shortened protein that may malfunction or not at all.
An Insertion happens when changes in the number of DNA bases in a gene are made by adding a piece of DNA. As a consequence, the protein built by the gene may not function correctly.
In Deletion, the mutation alters the number of DNA bases by deleting a piece of DNA. Small deletions can remove one or a few pairs of base within a gene. Large deletions can remove the entire gene or many of the nearby genes.
The Duplication mutation has a piece of DNA that is copied abnormally once or several times. It can change the function of the resulting protein just like in deletion.
For frameshift to happen, the addition or loss of DNA bases alters a gene's reading frame which composes of group of 3 bases, with each codes for an amino acid. The frameshift mutation shifts the grouping of the bases and modifies the code for amino acids. The protein that resulted is nonfunctional. Duplications, Insertions and Deletions can be frameshift mutation.
In Repeat expansion, the nucleotide repeats are short DNA sequences repeated a few times in a row. It is a mutation that raises the number of times that the short DNA sequence is repeated, and thus renders the protein to be malfunctional.
