What Is Gene Mutation

Molecule Tutorials - Herong's Tutorial Examples

∟What Is Gene Mutation

Provides a quick introduction of gene mutation, which is a slight alteration of DNA or RNA nucleotides, genes or chromosomes that may occur during replication or cell division.

What Is Gene Mutation? - Gene mutations are slight alterations of DNA or RNA nucleotides, genes or chromosomes that may occur during replication or cell division.

Gene mutations can be categorized in different ways.

The first example is to categorize gene mutations based on the genetic inheritance.

Germline mutation: This occurs in germ (egg and sperm) cells. From a parent point of view, this will be passed to the entire body of your child. From a child point of view, this is inherited from one of your parents.
Somatic mutation: This occurs in somatic (body) cells. From a parent point of view, this will not be passed to your child. From a child point of view, this is inherited if detected everywhere, or not-inherited if detected locally.

One example is to categorize gene mutations based on the context where the alteration takes place.

Tautomerism: This occurs during replication of DNA in the cell nucleus. Tautomers are mismatched pairs of nucleotide bases.
Depurination: This is a chemical reaction that happens when the bonds break between the deoxyribose sugar in DNA and the purine base of guanine or adenine. Losing a purine base is a common spontaneous mutation.
Deamination: This occurs if enzymes remove a nitrogen group from an amino acid. For instance, the (temperature-dependent) hydrolic deamination of cytosine to uracil is a leading cause of single-site, spontaneous mutations, as reported in the Proceedings of the National Academy of Sciences.
Transition and transversion: These mutations are two types of DNA substitution errors that involve switching of nucleotide base pairs.
Transition: This occurs due to a genetic shuffling of similarly shaped nucleotide bases. A transition mutation occurs when a wild-type (normally occurring) base pair like adenine and thymine are replaced by guanine and cytosine base pairs.
Transversion: This refers to the interchange of differently shaped purine and pyrimidine bases. For example, the mutated segment of DNA may have adenine replacing thymine.