Association between the DRD2 TaqIA gene polymorphism and Parkinson disease risk: an updated meta-analysis

Abstract

Background:DRD2 TaqIA polymorphism may be associated with an increased risk of developing Parkinson disease (PD). However, the individual study's results are still inconsistent.Methods:A meta-analysis of 4232 cases and 4774 controls from 14 separate studies were performed to explore the possible relationship between the DRD2 TaqIA gene polymorphism and PD. Pooled odds ratios (ORs) for the association and the corresponding 95% confidence intervals (CIs) were evaluated by a fixed-effect model.Results:The pooled results revealed a significant association between DRD2 gene TaqIA polymorphism under recessive genetic model (OR: 0.91, 95% CI:0.83,0.99, P = .031) and additive genetic models (OR:0.93,95%CI:0.87,0.99, P = .032), but not associated with PD susceptibility under other genetic models in the whole population. Moreover, subgroups based on ethnicity and genotyping methods showed this association in the Caucasian subgroup under recessive genetic model (OR: 0.85, 95% CI:0.76,0.95, P = .003) and additive genetic models (OR:0.87,95%CI:0.79,0.96, P = .004) were existed. Besides, no significant association was detected under 6 genetic models in the Asian populations and PCR-RFLP subgroup.Conclusions:The current meta-analysis suggested that a significant association between DRD2 TaqIA polymorphism and PD under the recessive genetic mode, and additive genetic models, especially in Caucasians.

Gastrointestinal Dopamine in Inflammatory Bowel Diseases: A Systematic Review

“…It should be also mentioned in this context that the D2R TaqIA polymorphism ( rs1800497 ) which confers a decreased receptor density was evaluated, and although the frequencies of the A1A1 and A2A2 genotypes were similar among CD patients, UC patients, and healthy controls, the CD carriers of the A2A2 genotype showed a lower risk for the development of refractory CD than A1A1 and A1A2 carriers [ 30 ]. Interestingly, a recent meta-analysis by You et al (2019) suggested a significant association between the D2R TaqIA polymorphism and PD in the recessive and additive genetic models, especially in Caucasians [ 73 ]. Pharmacologically, DA has a 10-time higher affinity for D5R than for D1R, and a 20-time higher affinity for D3R than for D2R [ 68 ], and thus can exert either immunosuppressive or pro-inflammatory roles depending on either its high or low tissue concentrations, respectively.…”

Nardosinone Alleviates Parkinson’s Disease Symptoms in Mice by Regulating Dopamine D2 Receptor

“…DA plays an important role in mediating the pathogenesis and treatment of PD. There are five types of dopamine receptors (DRD), namely, DRD 1-5 [ 44 ]. Among them, DRD2 has attracted considerable attention since its agonists can improve the motor symptoms of PD patients without exhibiting the side effects of movement disorders and mental illness.…”

Clustering of Parkinson subtypes reveals strong influence of DRD2 polymorphism and gender

“…(2) Gene polymorphism: Likewise, DRD2 Taq1A (rs1800497) and DRD3 Ser9Gly (rs6208) polymorphism might be of great importance when delineating PD subtypes 15 . An association of receptor polymorphisms—as disease causing variants—has been reported for Parkinson’s disease 16 , 17 . An influence of these polymorphisms on medication response and occurrence of side effects in individual patients is part of ongoing research 18 – 22 .…”