Suicidal Behavior and Haplotypes of the Dopamine Receptor Gene (DRD2) and ANKK1 Gene Polymorphisms in Patients with Alcohol Dependence – Preliminary Report

Abstract

Suicide is a significant public health issue and a major cause of death throughout the world. According to WHO it accounts for almost 2% of deaths worldwide. The etiology of suicidal behavior is complex but the results of many studies suggest that genetic determinants are of significant importance. In our study,- we have analyzed selected SNPs polymorphisms in the DRD2 and ANKK1 genes in patients with alcohol dependence syndrome (169 Caucasian subjects) including a subgroup of individuals (n = 61) who have experienced at least one suicide attempt. The aim of the study was to verify if various haplotypes of selected genes, comprising Taq1A, Taq1B, and Taq1D single nucleotide polymorphisms (SNP) play any role in the development of alcohol dependence and suicidal behavior. The control group comprised 157 unrelated individuals matched for ethnicity, gender,- and age and included no individuals with mental disorders. All subjects were recruited in the North West region of Poland. The study showed that alcohol dependent subjects with a history of at least one suicidal attempt were characterized by a significantly higher frequency of the T-G-A2 haplotype when compared to individuals in whom alcohol dependence was not associated with suicidal behavior (p = 0.006). It appears that studies based on identifying correlation between SNPs is the future for research on genetic risk factors that contribute to the development of alcohol addiction and other associated disorders. To sum up, there is a necessity to perform further research to explain dependencies between the dopaminergic system, alcohol use disorders and suicidal behavior.

Association between Polymorphisms of the DRD2 and ANKK1 Genes and Suicide Attempt: A Preliminary Case-Control Study in a Mexican Population

“…We found that our results are agreement with those of previous studies that indicate an association between Taq1A and suicidal behavior [12, 22]. In 2009, Suda et al [12], in a case-control study (120 suicide attempters and 123 controls), reported an association of the A2 allele of Taq1A (rs1800497T) in suicide attempters in Japan.…”

“…In 2009, Suda et al [12], in a case-control study (120 suicide attempters and 123 controls), reported an association of the A2 allele of Taq1A (rs1800497T) in suicide attempters in Japan. Recently, Jasiewicz et al [22] in Poland evaluated people with alcohol dependence and suicide attempt ( n = 61) and reported a haplotype that includes Taq1A (rs1800497T) associated with suicidal behavior. These positive associations and the results of the present study suggest a possible role of ANKK1 in suicidal behavior.…”

“…Due to the gene functions, several studies have investigated the association between ANKK1 and suicide behavior, suggesting that this polymorphism may play a role in suicide behavior [12, 22]. However, to date, no studies have evaluated the association between the polymorphism of dopaminergic D2 class receptors and/or the Taq1A polymorphism of ANKK1 and suicide attempt in a Mexican population.…”

Comportamentos suicidas em pessoas com transtornos relacionados a substâncias

“…70 Biochemical and genetic changes may favor the development of suicidal behavior, specifically in people with alcohol-related disorders. 32,36,59 A study that investigated the presence of abnormalities in the endocannabinoid system of suicidal people with alcohol-related disorders showed that there is higher levels of CB1 receptors in the ventral striatum and G protein signaling mediated by the CB1 receptor between alcoholics who committed suicide. 32 Some genetic changes act on the dopaminergic 59 and the serotoninergic 36 system, which may result in a higher probability of developing suicidal behavior in alcoholics.…”

Association of the SLC6A4, SLC6A3, COMT and BDNF Gene Polymorphisms with Suicidal Behavior: A Case Control Study

“…It was shown that T-allele carriers have a lower density of DRD2 receptors [32]. The DRD2 rs1800497 polymorphism is associated with impulsivity and suggested to be related to suicidal attempts [33,34]. The enzyme catechol-O-methyltransferase (COMT) plays an important role in dopamine metabolism.…”