Effect of monoamine oxidase B A644G variant on nicotine dependence and/or schizophrenia risk

Abstract

Objectives: Schizophrenia (Sch) is a severe and chronic mental illness. Smoking prevalence is higher in patients with Sch than general population. We aimed to investigate the effects of MAOB gene A644G variant on nicotine dependence (ND) and Sch+ND risk in Turkish population and to evaluate by bioinformatic analysis. Methods: Present study included 161 individuals with ND, 223 patients with Sch+ND, and 96 non-smoker controls. MAOB A644G variant was analyzed using PCR-RFLP method. As the MAOB gene is located on the X chromosome, each gender was analysed separately. Results: The total distributions of AA, AG and GG genotypes of MAOB gene A644G were 44.7%, 22.4% and 32.9% in the ND group, 45.3%, 25.1% and 29.6% in the Sch+ND group and, 44.8, 22.9% and 32.3% in non-smoker controls. No significant differences were observed between groups for the MAOB A644G genotype and allele frequencies when female group compared to male group (p > 0.05). Examination of disease associations of SNPs from each miRNA gene region in GWAS databases yielded results for aging, bipolar disorder, autoimmune, and neurological diseases. Discussion: Our results indicate that the MAOB gene A644G variant is not associated with ND and/or Sch susceptibility in the Turkish population.

Detention in Juvenile Correctional Facilities Is Associated with Higher Platelet Monoamine Oxidase B Activity in Males

“…In line with this finding, MAOB rs1799836 was not related to autism in children [ 62 , 63 ], severe agitation in patients with schizophrenia, CD, PTSD [ 23 , 30 ], anger-related traits and aggression in suicidal participants and controls [ 64 ], aggression determined using the Brown–Goodwin questionnaire [ 65 ], alcohol dependence [ 18 ], positive symptoms in schizophrenia [ 66 ], or negative emotionality in healthy subjects [ 67 ]. In contrast to our data, a moderate association of the G allele with higher scores on the Spontaneous Aggression subscale from the Freiburg Aggression Scale in alcohol-dependent patients [ 17 ], and the association with the development of schizophrenia in Han Chinese patients [ 68 ], but not in Turkish patients [ 69 ], was reported. MAOB rs1799836 might not be directly associated with CD or with delinquent behavior, but in a haplotype analysis with other polymorphisms, such as MAOA rs6323T [ 68 ] or MAOB rs1799836, rs10521432, rs6651806, and rs590551 [ 67 ], it might show significant association with altered behaviors.…”

Genetic variability in the neurobiology of nicotine dependence: effects on smoking behavior

“…Regarding variations in the MAOB gene, the A allele of the MAOB rs1799836 polymorphism (A> G) is associated with a lower risk of heavy smoking in men 72 . However, this association is contradicted by other studies 66,105 . Interactions between this SNP with other polymorphisms seem to interfere with the risk of smoking 70,73 .…”

Insights into the Promising Prospect of G Protein and GPCR-Mediated Signaling in Neuropathophysiology and Its Therapeutic Regulation

“…Catecholamine neurotransmitters, such as dopamine, are found in the brain [ 186 ]. Parkinson's disease, schizophrenia, obsessive-compulsive disorder, bipolar disorder, and hyperactivity-hyperactivity disorder are only a few of the CNS illnesses where dopamine plays a major role [ 187 , 188 ]. D1 and D2 dopamine receptors are two subclasses of G protein-coupled receptors (GPCRs), which are responsible for the action of dopamine.…”