genetic polymorphism


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Related to genetic polymorphism: Single nucleotide polymorphism

polymorphism

 [pol″e-mor´fizm]
the ability to exist in several different forms.
balanced polymorphism an equilibrium mixture of homozygotes and heterozygotes maintained by natural selection against both homozygotes.
genetic polymorphism the occurrence together in the same population of two or more genetically determined phenotypes in such proportions that the rarest of them cannot be maintained merely by recurrent mutation.
single nucleotide polymorphism (SNP) a genetic polymorphism between two genomes that is based on deletion, insertion, or exchange of a single nucleotide.

ge·net·ic pol·y·mor·phism

the occurrence in the same population of multiple discrete alletic states of which at least two have high frequency (conventionally of 1% or more).

genetic polymorphism

or

polymorphism

the presence in a population of two or more MORPHS, produced when different alleles of a gene occur in the same population and the rarest allele is not maintained merely by repeated MUTATION (i.e. has a frequency higher than, say, 0.05%). Such a definition excludes continuously variable characters such as height or skin colour in humans, but the human blood groups are classic examples, where single genes have two or more alleles, producing different antigenic phenotypes. A genetic polymorphism can be maintained by several mechanisms such as heterozygous advantage or FREQUENCY-DEPENDENT SELECTION, and can be stable over several generations (a BALANCED POLYMORPHISM) or may become ‘transient’ as when the environment changes; see, for example, SICKLE-CELL ANAEMIA.
References in periodicals archive ?
Lin et al., "Genetic polymorphism of cytochrome P4501A1 and susceptibility to oral squamous cell carcinoma and oral precancer lesions associated with smoking/betel use," Journal of Oral Pathology and Medicine, vol.
The role of TLR genetic polymorphisms of GC should be extensively evaluated by studying the distribution of TLR polymorphisms in the Thai population.
CYP3A4*1G genetic polymorphism influences CYP3A activity and response to fentanyl in Chinese gynecologic patients.
In the clinical analysis of the current study, which was performed according to the Revised Atlanta Classification, it was observed that the TLR4 Asp299Gly and Thr399Ile polymorphism and the TLR2 intron 2 microsatellite polymorphism did not create any significant differences in patients with different pancreatitis severities, and there was no connection between the genetic polymorphism and pancreatitis severity.
Correlation of genetic polymorphism has also been extensively studied in non-malignant diseases, as well as malignant diseases, and interestingly, were found to carry strong associations (18, 20).
Genetic polymorphisms -137 (rs187238) and -607 (rs1946518) in the interleukin-18 promoter may not be associated with development of hepatocellular carcinoma.
Genetic polymorphism of [beta]-lactoglobulin in native sheep from the island Pag.
Genetic polymorphisms involved with the NLRP3 inflammasome were linked to various diseases, such as rheumatoid arthritis, ankylosing spondylitis, melanoma, liver cancer, lung cancer, and ovarian cancer [7-9].
This study aims to evaluate whether the patients who applied to the emergency unit with supratherapeutic international normalized ratio (INR) levels after using warfarin were different as regards CYP2C9 and VKORC1 genetic polymorphisms than the control group patients with therapeutic INR levels.
After treatment of metformin consecutively for 12 weeks, some differences in genotype and allele frequencies in terms of STK11 rs2075604 genetic polymorphism appeared between the responders and nonresponders (Table 4).
Taking into account that the development and accumulation of granulomas constitute the fundamental abnormality in TB, it is tempting to hypothesize that genetic polymorphisms in MYD88, the common TLR signaling molecule, are associated with the disease.