Association of COMT rs4680 and MAO-B rs1799836 polymorphisms with levodopa-induced dyskinesia in Parkinson's disease-a meta-analysis.

background and purposePolymorphisms of the catechol-O-methyl transferase (COMT) or monoamine oxidase B (MAO-B) genes may affect the occurrence of dyskinesia in Parkinson's disease (PD) patients. However, the findings are inconsistent. Thus, we performed a meta-analysis to assess whether COMT and MAO-B genetic variants are associated with an increased incidence of levodopa-induced dyskinesia (LID) in PD patients.

methodsA literature search of PubMed, Embase, and Cochrane Library was conducted to identify relevant studies published up to January 2021. The strength of the association between the polymorphisms and LID susceptibility was estimated by odds ratio (OR) and associated 95% confidence interval (CI). The pooled ORs were assessed in different genetic models.

resultsTen studies involving 2385 PD patients were included in the meta-analysis. Analysis of pooled ORs and 95% CIs suggested that the AA genotype of COMT(rs4680) was associated with LID (OR = 1.39, 95%CI: 1.02-1.89, P = 0.039) in the recessive model, and this correlation was more obvious in Brazilian samples in the analysis stratified by ethnicity. For the AG genotype of MAO-B(rs1799836), the pooled OR was 1.66 (95% CI: 1.04-2.65, P = 0.03) in patients with LID versus those without LID in the heterozygote model.

conclusionsOur meta-analysis implicates the AA genotype of the COMT rs4680 polymorphism as potentially increasing the risk of LID in a recessive genetic model for PD patients. Furthermore, the AG genotype of the MAO-B rs1799836 polymorphism may influence the prevalence of LID in PD patients in the heterozygote model. However, further well-designed studies with larger PD patient cohorts are required to validate these results after adjusting for confounding factors.