C957T
Encyclopedia
The C957T gene polymorphism
is a synonymous mutation located within the 957th base pair
of the DRD2 gene. This base pair is located in exon
7. Most synonymous mutations are silent. However, the C957T mutation is an exception to this rule. While the 957C allele
codes for the same polypeptide as the 957T allele. The conformation
of 957T messenger RNA
differs from the conformation of 957C messenger RNA. 957T messenger RNA is less stable and more prone to degradation. As a result, dopamine D2 receptor expression is decreased among individuals who carry the 957C allele compared to individuals who carry the 957T allele.
Given that the C/C genotype has been associated with dissocial personality disorder one may infer that this genotype may also be associated with all four DSM-IV defined cluster B personality disorders
. This hypothesis, however, has not been tested.
Gene polymorphism
A gene is said to be polymorphic if more than one allele occupies that gene’s locus within a population....
is a synonymous mutation located within the 957th base pair
Base pair
In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair...
of the DRD2 gene. This base pair is located in exon
Exon
An exon is a nucleic acid sequence that is represented in the mature form of an RNA molecule either after portions of a precursor RNA have been removed by cis-splicing or when two or more precursor RNA molecules have been ligated by trans-splicing. The mature RNA molecule can be a messenger RNA...
7. Most synonymous mutations are silent. However, the C957T mutation is an exception to this rule. While the 957C allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...
codes for the same polypeptide as the 957T allele. The conformation
Conformation
Conformation generally means structural arrangement and may refer to:*Carbohydrate conformation, the three-dimensional shape of a carbohydrate...
of 957T messenger RNA
Messenger RNA
Messenger RNA is a molecule of RNA encoding a chemical "blueprint" for a protein product. mRNA is transcribed from a DNA template, and carries coding information to the sites of protein synthesis: the ribosomes. Here, the nucleic acid polymer is translated into a polymer of amino acids: a protein...
differs from the conformation of 957C messenger RNA. 957T messenger RNA is less stable and more prone to degradation. As a result, dopamine D2 receptor expression is decreased among individuals who carry the 957C allele compared to individuals who carry the 957T allele.
Behaviours associated with the C/C genotype of the C957T polymorphism
- schizophreniaSchizophreniaSchizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
- diminished working memory ability
- altered response to nicotineNicotineNicotine is an alkaloid found in the nightshade family of plants that constitutes approximately 0.6–3.0% of the dry weight of tobacco, with biosynthesis taking place in the roots and accumulation occurring in the leaves...
- reward related impulsivity
- sucrose addiction
- altered susceptibility to iatrogenic tardive dyskinesiaTardive dyskinesiaTardive dyskinesia is a difficult-to-treat form of dyskinesia that can be tardive...
- altered fear conditioningFear conditioningFear conditioning is a behavioral paradigm in which organisms learn to predict aversive events. It is a form of learning in which an aversive stimulus is associated with a particular neutral context or neutral stimulus , resulting in the expression of fear responses to the originally neutral...
- dissocial personality disorder
- posttraumatic stress disorder
Given that the C/C genotype has been associated with dissocial personality disorder one may infer that this genotype may also be associated with all four DSM-IV defined cluster B personality disorders
Cluster B personality disorders
Four cluster B personality disorders are described in DSM-IV:* Antisocial personality disorder : a pervasive disregard for the law and the rights of others....
. This hypothesis, however, has not been tested.