The Polymorphism And Clinical Phenotype Of COMT Gene In Early-Onset Parkinson's Disease

Background and Objective:Parkinson's disease(PD)is an elderly neurodegenerative disease that seriously affects the quality of life.The main pathological changes are due to the selective degeneration of dopaminergic neurons in the substantia nigra and the formation of Lewy bodies in the remaining neurons.Its main manifestations are bradykinesia,myotonia and resting tremor.The incidence of Early-onset Parkinson's Disease(EOPD)is relatively low,accounting for about 10% of Parkinson's disease.EOPD has clinical features such as slow progression,long course of disease,high incidence of dyskinesia,and high risk of non-exercise symptoms.Catechol-Omethyltransferase(COMT)is one of the enzymes involved in the metabolism of dopamine and other catecholamine neurotransmitters in the central and peripheral nervous systems.COMT is the major degrading enzyme of dopamine.The COMT gene rs4680 is the most common mutation site,and the mutated COMT gene changes the COMT activity.A number of studies have shown that the polymorphism of the rs4680 locus in the COMT gene may have an impact on the susceptibility,motor complications,non-motor symptoms and treatment of PD patients.Therefore,this study attempted to investigate the association between the polymorphism of the rs4680 locus of COMT gene and the clinical phenotype of EOPD patients.Materials and methods:A total of 75 patients diagnosed with Parkinson's disease in our neurology clinic from June 2018 to January 2019 were collected.Collect the patient's gender,age of onset,duration of disease,unilateral onset,first symptom,dyskinesia,onoff phenomenon,Unified Parkinson Disease Rating Scale(UPDRS),HY grading(HoehnYahr grating,HY),Hamilton Depression Scale(HAMD),Hamilton Anxiety Scale(HAMA),Mini-mental State Examination(MMSE),Pittsburgh Sleep quality refers to the Pittsburgh Sleep Quality Index(PSQI).The polymorphism of rs4680 in COMT gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism(PCRRFLP),and the related data were statistically analyzed.COMT gene polymorphism in patients with Parkinson's disease was treated with EOPD.The impact of clinical phenotypes.Results:(1)This study included 75 patients with early-onset Parkinson's disease(hereinafter referred to as EOPD)(age age ? 60 years),including 40 male patients(53.3%)and 35 female patients(46.7%).There were 45 cases(60%)? 50 years old,and 30 cases(40%)with age of onset > 50 years old.(2)The frequency distribution of three genotypes of COMT gene rs4680 in EOPD patients was 37(49.3%)of GG genotype,30(40%)of GA genotype,and 8(10.7%)of AA genotype.(3)There was no significant difference in the distribution of clinical phenotype between COMT GG genotype and GA+AA in EOPD patients in the overall sample(P>0.05);(4)After stratification by sex,male EOPD patients were in COMT GG The effect of genotype and GA+AA on clinical phenotype found that the distribution of MMSE was statistically significant(P=0.04).The effect of COMT GG genotype and GA+AA on clinical phenotype in female EOPD patients was found to be statistically significant(P=0.03).(5)The effect of COMT GG genotype and GA+AA on clinical phenotype was found to be statistically significant(P=0.03).Conclusion:(1)Male EOPD patients carrying the COMT gene A allele may increase the risk of cognitive impairment.(2)Women with EOPD who carry the COMT gene A allele may increase the risk of dyskinesia.(3)Carrying the COMT gene A allele in EOPD patients with an onset age >50 years may be a protective factor for the patient's motor symptoms.