Cancer<unk>  produces an amine oxidase, which is a class of enzyme known to affect carcinogenesis. Clorgyline, an<unk>  enzyme inhibitor, prevents apoptosis in melanoma cells, in vitro. Cholangiocarcinoma suppresses<unk>  expression, and those patients with higher<unk>  expression had less adjacent organ invasion and better prognosis and survival. Cardiovascular disease<unk>  activity is linked to apoptosis and cardiac damage during cardiac injury following ischemic-reperfusion. Behavioral and neurological disorders There is some association between low activity forms of the<unk>  gene and autism. Mutations in the<unk>  gene results in<unk> eficiency, or Brunner syndrome. Other disorders associated with<unk>  include Alzheimer's disease, aggression, panic disorder, bipolar affective disorder, major depressive disorder, and attention deficit hyperactivity disorder. Effects of parenting on self-regulation in adolescents appear to be moderated by 'plasticity alleles', of which the 2R and 3R alleles of<unk>  are two, with "the more plasticity alleles males (but not females) carried, the more and less self-regulation they manifested under, respectively, supportive and unsupportive parenting conditions." Depression<unk>  levels in the brain as measured using positron emission tomography are elevated by an average of 34% in patients with major depressive disorder. Genetic association studies examining the relationship between high-activity<unk>  variants and depression have produced mixed results, with some studies linking the high-activity variants to major depression in females, depressed suicide in males, major depression and sleep disturbance in males and major depressive disorder in both males and females. Other studies failed to find a significant relationship between high-activity variants of the<unk>  gene and major depressive disorder. In patients with major depressive disorder, those with<unk>  G/T polymorphisms (rs6323) coding for the highest-activity form of the enzyme have a significantly lower magnitude of placebo response than those with other genotypes. Antisocial behavior In humans, an association between the 2R allele of the VNTR region of the gene and an increase in the likelihood of committing serious crime or violence has been found. The VNTR 2R allele of<unk>  has been found to be a risk factor for violent delinquency, when present in association with stresses, i.e. family issues, low popularity or failing school. A connection between the<unk>  gene 3R version and several types of anti-social behaviour has been found: Maltreated children with genes causing high levels of<unk>  were less likely to develop antisocial behavior. Low<unk>  activity alleles which are overwhelmingly the 3R allele in combination with abuse experienced during childhood resulted in an increased risk of aggressive behaviour as an adult, and men with the low activity<unk>  allele were more genetically vulnerable even to punitive discipline as a predictor of antisocial behaviour. High testosterone, maternal tobacco smoking during pregnancy, poor material living standards, dropping out of school, and low IQ predicted violent behavior are associated with men with the low-activity alleles.According to a large meta-analysis in 2014, the 3R allele had a small, nonsignificant effect on aggression and antisocial behavior, in the absence of other interaction factors. Owing to methodological concerns, the authors do not view this as evidence in favor of an effect. The<unk>  gene was the first candidate gene for antisocial behavior and was identified during a "molecular genetic analysis of a large, multigenerational, and notoriously violent, Dutch kindred". A study of Finnish prisoners revealed that a<unk> -L (low-activity) genotype, which contributes to low dopamine turnover rate, was associated with extremely violent behavior. For the purpose of the study, "extremely violent behavior" was defined as at least ten committed homicides, attempted homicides or batteries. However, a large genome-wide association study has failed to find any large or statistically significant effects of the<unk>  gene on aggression. A separate GWAS on antisocial personality disorder likewise did not report a significant effect of<unk> . Another study, while finding effects from a candidate gene search, failed to find any evidence in a large GWAS. A separate analysis of human and rat genome wide association studies, Mandelian randomization studies, and causal pathway analyses likewise failed to reveal robust evidence of<unk>  in aggression. This lack of replication is predicted from the known issues of candidate gene research, which can produce many substantial false positives. Aggression and the "Warrior gene" Low-activity variants of the VNTR promoter region of the<unk>  gene have been referred to as the warrior gene. While almost all humans have a functional<unk>  gene,<unk>  deficiency has been seen in at least 5 families with Brunner syndrome. Given that<unk>  degrades amine neurotransmitters, gene variants could affect a person's personality or behaviour. When faced with social exclusion or ostracism, individuals with the low activity<unk>  variants showed higher levels of aggression than individuals with the high activity<unk>  gene. Low activity<unk>  could significantly predict aggressive behaviour in a high provocation situation, but was less associated with aggression in a low provocation situation. Individuals with the low activity variant of the<unk>  gene were just as likely as participants with the high activity variant to retaliate (by administering hot sauce to an opponent) when the loss was small. However, they were more likely (75% as opposed to 62%, out of a sample size of 70) to retaliate and with greater force when the loss was large. The effects of<unk>  genes on aggression have also been criticized for being heavily overstated. Indeed, the<unk>  gene, even in conjunction with childhood adversity, is known to have a very small effect. The vast majority of people with the associated alleles have not committed any violent acts. Legal implications In a 2009 criminal trial in the United States, an argument based on a combination of "warrior gene" and history of child abuse was successfully used to avoid a conviction of first-degree murder and the death penalty; however, the convicted murderer was sentenced to 32 years in prison. Epigenetics Studies have linked methylation of the<unk>  gene with nicotine and alcohol dependence in women. A second<unk>  VNTR promoter, P2, influences epigenetic methylation and interacts with having experienced child abuse to influence antisocial personality disorder symptoms, only in women.
Monoamine oxidase A
Monoamine oxidase B
Catechol-O-methyltransferase
Tyrosine hydroxylase
Phenylalanine hydroxylase
Aromatic L-amino acid decarboxylase
Glutamate dehydrogenase
Dopamine beta-hydroxylase