Mutation

An alteration in DNA structure or sequence of a gene. (See Point mutation.)

Any change in the genome with respect to a defined wild type. Can occur at the level of ploidy, karyotype, or nucleotide sequence. Most of the latter mutations are silent (i.e. cannot be associated with any change in phenotype ), either because the DNA sequence affected is in the non-coding part of the genome, or because the specific change does not alter the function of a coding sequence. See: back mutation, single nucleotide polymorphism.

Any inheritable change in DNA sequence.

(myoo-TAY-shun) Any change in the DNA of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited. Certain mutations may lead to cancer or other diseases.

A permanent structural alteration in DNA. In most cases, DNA changes either have no effect or cause harm, but occasionally a mutation can improve an organism's chance of surviving and passing the beneficial change on to its descendants. See also

Any heritable change in DNA sequence. See also: polymorphism