ANKK1
Encyclopedia
The ANKK1 gene is a member of an extensive family of proteins involved in signal transduction pathways. This gene contains a single nucleotide polymorphism
that causes an amino acid substitution within the 11th of 12 ankyrin repeat
s of ANKK1 (Glu713Lys of 765 residues
). This polymorphism, which is commonly referred to Taq1A, was previously believed to be located in the promoter region of the DRD2 gene, since the polymorphism is proximal to the DRD2 gene and can influence DRD2 receptor expression. It is now known to be located in the coding region of the ANKK1 gene which controls the synthesis of dopamine
in the brain. The A1 allele is associated with increased activity of striatal L-amino acid decarboxylase.
Given that the A1+ allele is associated with dissocial personality disorder, one may infer that the allele is also associated with narcissistic personality disorder
and histrionic personality disorder
. However, these predictions have not yet been empirically verified.
Single nucleotide polymorphism
A single-nucleotide polymorphism is a DNA sequence variation occurring when a single nucleotide — A, T, C or G — in the genome differs between members of a biological species or paired chromosomes in an individual...
that causes an amino acid substitution within the 11th of 12 ankyrin repeat
Ankyrin repeat
The ankyrin repeat is a 33-residue motif in proteins consisting of two alpha helices separated by loops, first discovered in signaling proteins in yeast Cdc10 and Drosophila Notch. Ankyrin repeats mediate protein–protein interactions and are among the most common structural motifs in known proteins...
s of ANKK1 (Glu713Lys of 765 residues
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
). This polymorphism, which is commonly referred to Taq1A, was previously believed to be located in the promoter region of the DRD2 gene, since the polymorphism is proximal to the DRD2 gene and can influence DRD2 receptor expression. It is now known to be located in the coding region of the ANKK1 gene which controls the synthesis of dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
in the brain. The A1 allele is associated with increased activity of striatal L-amino acid decarboxylase.
A1+ allele
- Hepatitis C infectionHepatitis CHepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years...
- Antisocial personality disorderAntisocial personality disorderAntisocial personality disorder is described by the American Psychiatric Association's Diagnostic and Statistical Manual, fourth edition , as an Axis II personality disorder characterized by "...a pervasive pattern of disregard for, and violation of, the rights of others that begins in childhood...
- Borderline personality traitsBorderline personality disorderBorderline personality disorder is a personality disorder described as a prolonged disturbance of personality function in a person , characterized by depth and variability of moods.The disorder typically involves unusual levels of instability in mood; black and white thinking, or splitting; the...
- Dissocial personality disorder
- Schizoid/avoidant behaviorSchizoid avoidant behaviorSchizoid personality disorder and avoidant personality disorder have both been associated with the same polymorphism within the ANKK1 gene. It remains unclear if these two personality disorders are linked to genetically distinct, but overlapping, personality disorders or if these two personality...
Given that the A1+ allele is associated with dissocial personality disorder, one may infer that the allele is also associated with narcissistic personality disorder
Narcissistic personality disorder
Narcissistic personality disorder is a personality disorder in which the individual is described as being excessively preoccupied with issues of personal adequacy, power, prestige and vanity...
and histrionic personality disorder
Histrionic personality disorder
Histrionic personality disorder is defined by the American Psychiatric Association as a personality disorder characterized by a pattern of excessive emotionality and attention-seeking, including an excessive need for approval and inappropriately seductive behavior, usually beginning in early...
. However, these predictions have not yet been empirically verified.