Somatic Mutation

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Related to Somatic Mutation: Somatic hypermutation

somatic mutation

[sō¦mad·ik myü′tā·shən]
A genetic change limited to a somatic cell lineage; a major cause of cancer in humans.

Mutation, Somatic


a mutation that occurs in a somatic cell and provides the basis for a mosaic condition, that is, the formation of certain body parts, tissues, or cells having a unique set of chromosomes or genes.

All the types of somatic mutations that occur in sexual cells may occur in the cells of a developing organism. These mutations include (1) an increase in the chromosome set as a whole after normal chromosomal division without the subsequent division of the nucleus and cell, (2) trisomy and monosomy of various chromosomes as a result of the migration of two daughter chromosomes to a single pole (instead of different poles), and (3) the loss of a chromosome in one of the daughter cells during division as a result of its entrapment in the zone of the equatorial plate.

Inversions, deletions, and translocations of chromosomal fragments and mutations of individual genes occur with varying frequency in somatic cells. The earlier a somatic mutation occurs in an organism’s development, the greater the number of cells that will inherit the mutation, provided that the mutation does not destroy the carrier cell and that the rate of the carrier cell’s proliferation does not decrease. Gene somatic mutations are manifested relatively rarely, because in the overwhelming majority of cases the function of the mutant gene or of the separated chromosomal fragment is compensated for by the presence of a normal homologous gene or a normal area in the homologous matching chromosome of a mutant chromosome. The manifestation of certain somatic mutations is suppressed by the proximity of normal tissue.

Somatic mutations may not be manifested when the corresponding part of a chromosome of the given tissue is inactive. In the early 1960’s it was established that somatic mutations play an important role in the pathogenesis of the abnormal development of the sexual system, in the causation of spontaneous abortions and congenital deformities, and in carcinogenesis.

In plants, cells that carry somatic mutations may be propagated vegetatively or when the mutant area forms flowers.


Vakhtin, Iu. B. Genetika somaticheskikh kletok. Moscow, 1974.


References in periodicals archive ?
One straightforward, heuristic approach to identifying relevant cancer genes from somatic mutation profiles involves characterizing the pattern of recurrent alterations across a large population.
Together, these studies have provided critical new insights into the molecular features of serous and endometrioid endometrial carcinomas, including the first observation (reported by TCGA)-based on an integrated analysis of somatic mutation rates, frequency of copy number alterations, and MSI status--that endometrial carcinomas can be broadly classified into 4 distinct molecular subgroups.
A reconsideration of the somatic mutation theory of cancer in the light of some recent developments.
To date 192 out of the 193 studied drug targets so far have been recorded with somatic mutations.
Based on its success in Europe, with sales in 2013 estimated at[euro]3M (CAGR%>100%) and with the launch of new products for both genomic and somatic mutations, Multiplicom is now also looking for additional growth in other major territories.
In light of these observations, plasma DNA assays for the detection of mutations in codon 12 of K-ras do not provide a reliable method to screen populations for the somatic mutations frequently found in neoplasms.
My approach will be to use data from multiple tumour genomes to estimate somatic mutations rates across the non-coding genome, adjusting for confounding effects, and to prioritize regions with a high somatic mutation rate and with high evolutionary conservation.
A close association has been reported between a somatic mutation, GAT (Asp), in codon 12 and distant hematogenous metastasis (22).
DDR genes protect against cancer, as demonstrated by their somatic mutation or epigenetic silencing being common in cancers.
Mutation analysis of the BRCA1 gene in 76 Japanese ovarian cancer patients: four germline mutations, but no evidence of somatic mutation.
The second paper, entitled "Prospective blinded study of somatic mutation detection in cell-free DNA utilizing a targeted 54-gene next generation sequencing panel in metastatic solid tumor patients," by Kim et al.
While clinical laboratories that have adopted somatic mutation detection by next-generation sequencing typically maintain their own mixtures of diluted cell-line DNA, they will not have the breadth of mutations, mutation types, or the ability to probe the lower limit of variant frequencies they can detect with their assays.