Difference Between Gene Mutation and Chromosome Mutation

Gene Mutation vs Chromosome Mutation

Mutations are the changes that occur in the genetic material of organisms, and those take place due to various reasons. Gene mutations and chromosome mutations are the two basic types of mutations, and those vary from each other mainly in the magnitude of the alteration. Mutations take place mainly because of erratic steps in regulation of DNA replication and transcription, exposure to radiations, and viruses. However, mutations may or may not be favourable for the persistence in the world over a long time. Individuals or populations with favourable genes will survive while the others are eliminated through natural selection.

Gene Mutation

Gene mutation is a small-scale alteration of the genetic material of an organism, which primarily is a change in the nucleotide sequence of a particular gene. These changes are of two types based on the way those take place. Point mutations and frame shift mutations are the two main types, but the frame shift mutations take place as either deletions or insertions. When a nucleotide of a particular gene is changed, the transcribe mRNA and the subsequent codons and synthesized amino acids are altered. However, there are few other sub types of point mutations known as Transition, Transversion, Silent, Missense, and Nonsense. The frame shift mutations, aka framing error, take place after the transcription of protein synthesis, as an extra nucleotide is attached (insertion) to the dismantled DNA strand. Additionally, there could be a chance of losing a nucleotide from the unwound DNA strand after the transcription.

Gene mutation may lead to alter the number or the structure of the entire chromosome, which could lead to chromosomal mutations. However, gene mutations are small-scale alterations in the nucleotide sequence and those are sometimes corrected through gene regulatory mechanisms but sometimes not. Some of the problems that are evident of a gene mutation cause are the sickle cell anaemia and lactose intolerance.

Chromosome Mutation

Chromosome mutation is a large-scale alteration of the chromosomes of an organism, where either the number or the structure of chromosomes is changed. There are three main types of chromosomal mutations known as Duplications, Inversions, and Deletions. When a particular part of the DNA strand is duplicated or doubled, the number of genes in a chromosome will increase, which cause both structural and numerical alteration to the chromosome. Sometimes a portion containing genes in the DNA strand gets removed and joined inversely to the original position, which results an inversion. Inversions do not cause the number to change, but different interactions may be resulted as the gene order has been changed; hence, the phenotypes become different. Deletions may take place due to exposure on radiation, high heat, or viruses. Usually, deletions are results of external causes, and the affected area of the chromosome determines the extent of change or the damage.

All these chromosomal mutations seriously affect the structure, and the number of chromosomes in an organism and the eventual protein syntheses and gene expression will be altered. Prader-Willi Syndrome and Cri-du-chat syndrome are some of the examples of chromosome mutations taken place through deletions.

What is the difference between Gene Mutation and Chromosome Mutation?

• Gene mutation is a change in the nucleotide sequence, in a particular gene, whereas chromosomal mutation is a change in several genes, in the chromosome.

• Gene mutation is a small-scale alteration, but chromosome mutation can be considered as a serious alteration.

• Gene mutations can sometimes be corrected, but chromosomal mutations are hardly corrected.

• Gene mutation is only a slight structural alteration, whereas chromosomal mutations are either numerical or structural changes in the entire DNA strand.