Mutation
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mutation
[mu-ta´shun]1. a permanent transmissible change in the genetic material.
2. an individual exhibiting such a change.
point mutation a mutation resulting from a change in a single base pair in the DNA molecule.
somatic mutation a genetic mutation occurring in a somatic cell, providing the basis for mosaicism.
suppressor mutation the correction of the effect of a mutation at one locus by a mutation at another locus.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
mu·ta·tion
(myū-tā'shŭn),1. A change in the chemistry of a gene that is perpetuated in subsequent divisions of the cell in which it occurs; a change in the sequence of base pairs in the chromosomal molecule.
2. De Vries, term for the sudden production of a species, as distinguished from variation.
[L. muto, pp. -atus, to change]
Farlex Partner Medical Dictionary © Farlex 2012
mutation
(myo͞o-tā′shən)n.
1. The act or process of being altered or changed.
2. An alteration or change, as in nature, form, or quality.
3. Genetics
a. A change in the nucleotide sequence of the genome of an organism or virus, sometimes resulting in the appearance of a new character or trait not found in the parental type.
b. The process by which such a change occurs, either through an alteration in the nucleotide sequence coding for a gene or through a change in the physical arrangement of the genetic material.
c. The nucleotide sequence, trait, or individual that results from such a change.
mu·ta′tion·al adj.
mu·ta′tion·al·ly adv.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
mutation
(1) The process by which genes undergo a permanent and heritable change in nucleotide sequence that differs from either parental haploid contribution to the progeny.(2) A heritable change in a DNA sequence.
Mutations either occur spontaneously or result from environmental exposure to mutagenic agents (e.g., chemicals, radiation). Most mutations either have no effect, are deleterious, or are lethal; some provide survival benefits, which are passed on to progeny.
Examples
Deletions, duplications, extranuclear changes, insertions, point mutations, rearrangements, tandem repeat amplifications, translocations.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
mu·ta·tion
(myū-tā'shŭn)1. A change in the chemistry of a gene that is perpetuated in subsequent divisions of the cell in which it occurs; a change in the sequence of base pairs in the chromosomal molecule.
2. The sudden production of a species, as distinguished from variation.
[L. muto, pp. -atus, to change]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
mutation
Any persisting change in the genetic material (DNA) of a cell. Mutations most commonly involve a single gene but may affect a major part, or even the whole of, a chromosome or may change the number of chromosomes (genomic mutation). A nonsense mutation is one that alters the sequence of bases in a CODON so that no amino acid is coded. Many mutations have an unfavourable effect on the cell concerned and are not passed on, but non-lethal mutations are replicated in daughter cells. Mutation in a cell in the GONADS that gives rise to a SPERMATOZOON or an egg (OVUM), will be passed on to a clone of sperms or eggs and one of these may take part in fertilization so that the mutation is passed on to every cell in the body of the future individual, including the GERM CELLS. New mutations occurring in the sex cells (germ line mutations) may thus lead to hereditary abnormalities. Mutations in body cells (somatic mutations) cannot do this but can cause cloned abnormalities including cancers. See also FRAME SHIFT MUTATION, INSERTION MUTATION, INVERSION MUTATION, LEAKY MUTATION, LETHAL MUTATION, MISSENSE MUTATION, POINT MUTATION, NONSENSE MUTATION.Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
mutation
a change in the genetic material of an organism. In eukaryotes, if the alteration affects gametic cells the change is a genetic mutation and can be inherited; if body cells (nonsexual) are affected the mutation is called somatic mutation and will not normally be inherited. Mutations that result in alterations to a gene produce a different ALLELE. Mutation can also affect the number of chromosomes. See also SPONTANEOUS MUTATION, INDUCED MUTATION, CHROMOSOMAL MUTATION.Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
Mutation
A permanent change in the genetic material that may alter a trait or characteristic of an individual, or manifest as disease, and can be transmitted to offspring.
Mentioned in: Achondroplasia, Ataxia-Telangiectasia, Colon Cancer, Familial Polyposis, Genetic Testing, Hemophilia, Lesch-Nyhan Syndrome, Monkeypox, Neurofibromatosis, Osteogenesis Imperfecta, Pervasive Developmental Disorders, Phenylketonuria, Prader-Willi Syndrome, Pseudoxanthoma Elasticum, Pyruvate Kinase Deficiency, Rectal Cancer, Sickle Cell Disease, Thalassemia, Von Willebrand Disease, Wiskott-Aldrich Syndrome, X-Linked Agammaglobulinemia
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
mutation
A permanent transmissible change in the nucleotide sequence of the DNA within a gene, or a change in the physical structure of a chromosome. It can occur by substitution (one base or nucleotide is replaced by another), transition (a purine (adenine or guanine) is replaced by another purine or one pyrimidine (cytosine or thymine) is replaced by another pyrimidine), transversion (a pyrimidine is replaced by a purine or vice versa), deletion or insertion of one or more bases. Mutations can also occur in a chromosome as a result of inversion (a segment of chromosome is inserted in reverse order), deletion (a loss of a piece of chromosome) or translocation (a piece of chromosome attaches to another). Mutations result in the formation of a protein with an abnormal amino acid or an absence of the protein and these may result in disease but some mutations may be beneficial. Mutations may be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation (X-rays, gamma rays), carcinogens, viruses, or spontaneously. See chromosome; gene.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
mu·ta·tion
(myū-tā'shŭn)Change in gene chemistry perpetuated in subsequent divisions of cell in which it occurs.
[L. muto, pp. -atus, to change]
Medical Dictionary for the Dental Professions © Farlex 2012