Association between dopamine receptor D2 Taq IA gene polymorphism and persistent postural-perceptual dizziness

BACKGROUND: Persistent postural-perceptual dizziness (PPPD) is a chronic dizziness, its pathogenesis is unknown by now. OBJECTIVE: To study the relationship between the DRD2 gene TaqIA polymorphisms and PPPD, and further to explore the molecular mechanism underlying this disease. METHODS: 43 patients diagnosed with PPPD and 45 randomly selected cases (matched by age and sex) were included in the study and control group, respectively. DRD2 gene TaqIA polymorphisms were detected in all participants by polymerase chain reaction (PCR)combined with the restriction fragment length polymorphism (RFLP) method. RESULTS: In the study group, frequencies of the A1 and A2 TaqIA alleles (65.1% and 34.9%, respectively) were significantly different to those in the control group (46.7% and 53.3%, respectively; P < 0.05). The allele frequency in the study group for the A1/A1 genotype was 34.9%, for A1/A2 was 60.5%, and for A2/A2 was 4.6%, all of which were significantly higher than the control group (24.4%, 44.5%. and 31.1%, respectively; P < 0.01). CONCLUSIONS: Our findings indicate that the DRD2 TaqIA A1 allele is possibly the susceptibility polymorphism for PPPD, and that the A2/A2 genotype has a potentially protective role for PPPD. However, larger independent studies are required for further validation.