Association study of α-synuclein gene polymorphism and non motor symptoms in Parkinson's disease

Objective To investigate the association between the single nucleotide polymorphisms (SNPs) rs894278 and rs11931074 of α-synuclein (SNCA) and non motor symptoms in Parkinson' s disease (PD).Methods One hundred and twenty PD patients and 100 healthy controls enrolled from Tonglu Hospital Affiliated to Ruijin Hospital and Ruijin Hospital,Shanghai Jiaotong University School of Medicine from 2012 to 2014 were recruited and the motor subscale of the Unified Parkinson' s Disease Rating Scale Ⅲ (UPDRS-Ⅲ) was used to evaluate motor function.The Mini-Mental State Examination (MMSE),17-item Hamilton Rating Scale (HAMD-17),the Rapid Eye Movement Behavior Disorder Screening Questionnaire (RBDSQ) and the ROME-Ⅲ criteria for chronic constipation were used to evaluate non motor symptoms.SNCA SNPs (rs894278,rs11931074) were genotyped by direct sequencing.Results There was no statistically significant difference in age,sex,non motor symptoms scores among the three genotypes of the two SNPs in control group.There was no statistically significant difference in age,sex,UPDRS-Ⅲ scores and Hoehn-Yahr stage among the three genotypes of the two SNPs in PD group.The results demonstrated that there was no association between the two SNPs and RBDSQ scores,HAMD-17 scores,MMSE scores and constipation in PD patients.However,additional analysis showed that patients with GG rs894278 had a greater proportion of clinical probable RBD than those with GT and TT types (GG 52.2％,12/23;GT 18.2％,10/55;TT 21.4％,9/42;x2 =9.254,P=0.002;x2 =6.424,P=0.005).In Logistic regression analyses adjusting for age and sex,we observed that rs894278 GG genotype could increase the risk of RBD in PD patients (OR =5.367,95％ CI =1.607-17.925,P =0.006).There was no association of RBD with allelic and genotypic distributions of SNCA rs11931074.Conclusion The results indicate that the rs894278 polymorphism correlates with RBD,while rs11931074 does not.