Chinese Parkinson's Disease Patients Research Articles

Disease duration-related differences in non-motor symptoms: A study of 616 Chinese Parkinson's disease patients

The differences in non-motor symptoms (NMS) along with the duration of Parkinson's disease (PD) in Chinese populations remain largely unknown. A total of 616 PD patients consisting of 189 patients with disease duration of less than 2years, 239 patients with duration between 2 and 5years, 122 patients with duration between 5 and 10years, and 66 patients with duration more than 10years from Southwest China were studied. Each patient was assessed using the non-motor symptoms scale (NMSS). The mean affected number of NMS was 8.8±5.8, and the mean total NMSS score was 36.3±33.2. The mean affected number of NMS and the mean total NMSS score increased with the disease progression. The following symptoms became more common and severe with the disease duration: falls due to fainting, fatigue, difficulty falling asleep, restless legs, perceptual problem/hallucination domain (i.e., “hallucinations,” “delusions,” and “double vision”), gastrointestinal domain (i.e., “dribbling saliva,” “swallowing,” and “constipation”), urinary domain (i.e., “urgency,” “frequency,” and “nocturia”), and miscellaneous domain (i.e., “excessive sweating”). However, some symptoms such as mood/apathy pleasure, sexual dysfunction, and others remained stable. NMS are prevalent in all disease duration of the Chinese PD patients. Although the mean affected number of NMS and NMMS score increased with the disease duration, NMS progression is symptom specific.

Subjective poor sleep quality in Chinese patients with Parkinson's disease without dementia

Parkinson's disease (PD) is a common progressive neurological disorder and is composed of motor and non-motor symptoms. Sleep disturbances are frequent problems for patients with PD. The relationship between sleep disturbances with Hoehn and Yahr (H&Y) staging have been demonstrated. However, the relationship between sleep disorders and H&Y is still unclear in patients with PD without dementia in Chinese PD patients. In this study, we interviewed 487 non-demented PD patients of Chinese Han descents by H&Y classification. We found that night sleep quality was significantly associated with the severity of PD (P = 0.008). Panic disorder severity scale (PDSS) total scores were correlated with PD non-motor symptoms scale (PDNMS) scores (r = -0.528, P < 0.001), the Hamilton depression scale (HAMD) scores (r = -0.545, P < 0.001) and the Hamilton anxiety scale (HAMA) scores (r = -0.498, P < 0.001). Our results indicated that sleep quality deteriorated with the advancing of PD in Chinese non-demented patients with PD. Depression and anxiety may partly explain sleep disturbances in non-demented patients with PD.

C9orf72 mutation is rare in Alzheimer's disease, Parkinson's disease, and essential tremor in China.

GGGGCC repeat expansions in the C9orf72 gene have been identified as a major contributing factor in patients with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Given the overlapping of clinical phenotypes and pathological characteristics between these two diseases and Alzheimer's disease (AD), Parkinson's disease (PD), and essential tremor (ET), we speculated regarding whether C9orf72 repeat expansions also play a major role in these three diseases. Using the repeat-primed polymerase chain reaction method, we screened for C9orf72 in three groups of patients with PD (n = 911), AD (n = 279), and ET (n = 152) in the Chinese Han population. There were no pathogenic repeats (>30 repeats) detected in either the patients or controls (n = 314), which indicated that the pathogenic expansions of C9orf72 might be rare in these three diseases. However, the analysis of the association between the number of repeats (p = 0.001), short/intermediate genotype (short: <7 repeats; intermediate: ≥7 repeats) (odds ratio 1.37 [1.05, 1.79]), intermediate/intermediate genotype (Odds ratio 2.03 [1.17, 3.54]), and PD risks indicated that intermediate repeat alleles could act as contributors to PD. To the best of our knowledge, this study is the first to reveal the correlation between C9orf72 and Chinese PD, AD, or ET patients. Additionally, the results of this study suggest the novel idea that the intermediate repeat allele in C9orf72 is most likely a risk factor for PD.

Association of polymorphism in rs2736990 of the α-synuclein gene with Parkinson′s disease in a Chinese population

Previous genetic studies in Parkinson's disease (PD) have provided conclusive evidence for association of genes with strong biological rationale for PD. Recently several studies in different populations have found a strong association between idiopathic PD and the single-nucleotide polymorphism (SNP) rs2736990, located within an intron of the α-synuclein (SNCA) gene. In this study, we aimed to verify these findings and to explore the characteristic of the association in a subset of Chinese Han PD patients. A total of 515 unrelated patients with sporadic PD and 450 healthy ethnically matched control subjects were recruited consecutively for the study. Patients and healthy controls were genotyped for SNCA rs2736990 variant by polymerase chain reaction - ligase detection reaction. Our data showed a significant association between the rs2736990 polymorphism and PD, the frequency of the allele C in PD patients was significantly higher than that in controls (P = 0.017, OR = 1.26, 95% confident intervals (CI) =1.04-1.51). The distribution of C > T genotypes was different between patients and controls (P = 0.027). Furthermore, allele C of SNP rs2736990 in early-onset PD was significantly more frequent than that in healthy controls (P = 0.007, odds ratio = 1.60, 95% CI = 1.13-2.26). Our study demonstrated that SNCA rs2736990 C > T polymorphism was associated with susceptibility to PD in Chinese Han population. Further studies are needed to replicate the association we found.

VPS35 Asp620Asn and EIF4G1 Arg1205His mutations are rare in Parkinson disease from Southwest China

The Asp620Asn mutation in the vacuolar protein sorting protein 35 (VPS35) gene and the Arg1205His mutation in the eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) gene were identified in autosomal dominant late-onset familial and sporadic Parkinson disease (PD) patients in a Caucasian population. However, the frequencies of these 2 mutations among Chinese PD patients are unknown. We examined these mutations in a large cohort consisting of 609 PD patients and 600 healthy control subjects from Southwest China. Our results suggest that the Asp620Asn mutation in VPS35 and the Arg1205His mutation in EIF4G1 do not play a role in PD in the Southwest China population. The novel Arg1205Cys mutation in EIF4G1 detected in the current study should be further studied among other Asian patients.

Association of Mitochondrial DNA Polymerase γ Gene POLG1 Polymorphisms with Parkinsonism in Chinese Populations

BackgroundMitochondrial DNA polymerase gamma (POLG1) mutations were associated with levodopa-responsive Parkinsonism. POLG1 gene contains a number of common nonsynonymous SNPs and intronic regulatory SNPs which may have functional consequences. It is of great interest to discover polymorphisms variants associated with Parkinson's disease (PD), both in isolation and in combination with specific SNPs.Materials and MethodsWe conducted a case-control study and genotyped twenty SNPs and poly-Q polymorphisms of POLG1 gene including in 344 Chinese sporadic PD patients and 154 healthy controls. All the polymorphisms of POLG1 we found in this study were sequenced by PCR products with dye terminator methods using an ABI-3100 sequencer. Hardy-Weinberg equilibrium and linkage disequilibrium (LD) for association between twenty POLG1 SNPs and PD were calculated using the program Haploview.Principal ResultsWe provided evidence for strong association of four intronic SNPs of the POLG1 gene (new report: c.2070-12T>A and rs2307439: c.2070-64G>A in intron 11, P = 0.00011, OR = 1.727; rs2302084: c.3105-11T>C and rs2246900: c.3105-36A>G in intron 19, P = 0.00031, OR = 1.648) with PD. However, we did not identify any significant association between ten exonic SNPs of POLG1 and PD. Linkage disequilibrium analysis indicated that c.2070-12T>A and c.2070-64G>A could be parsed into one block as Haplotype 1 as well as c.3105-11T>C and c.3105-36A>G in Haplotype 2. In addition, case and control study on association of POLG1 CAG repeat (poly-Q) alleles with PD showed a significant association (P = 0.03, OR = 2.16) of the non-10/11Q variants with PD. Although intronic SNPs associated with PD didn't influence POLG1 mRNA alternative splicing, there was a strong association of c.2070-12T>A and c.2070-64G>A with decreased POLG1 mRNA level and protein levels.ConclusionsOur findings indicate that POLG1 may play a role in the pathogenesis of PD in Chinese populations.

Association of HLA locus variant in Parkinson's disease

A variant (rs3129882) in the genome-wide association study (GWAS)-linked variant [in the human leukocyte antigen (HLA) gene region] has been reported to associate with an increased risk of Parkinson's disease (PD) in Caucasian population. Studies among Chinese are limited. To address this, we analysed rs3129882 in a total of 1312 subjects of Chinese ethnicity from independent Asian centers comprising of 675 controls and 637 PD cases. The rs3129882 variant was associated with a decreased risk in our ethnic Chinese PD patients. Logistic regression analysis taking into consideration variables of age, gender and race showed that allele A reduced the risk of PD via a dominant model [odds ratio (OR) = 0.77, 95% confidence interval (CI) = 0.62, 0.96, p = 0.018]. As HLA is a highly polymorphic region, it is possible that ethnic-specific effect or environmental agents may modulate the effect of this GWAS-linked locus in influencing the risk of PD.

Vacuolar protein sorting 35 Asp620Asn mutation is rare in the ethnic Chinese population with Parkinson's disease

Vacuolar protein sorting 35 (VPS35) Asp620Asn mutation has been identified in late-onset familial Parkinson's disease (PD) patients of Swiss and Austrian descent as well as sporadic PD patients in the United States. In order to determine the contribution of VPS35 mutations in mainland Chinese PD patients and to better understand the association between VPS35 and PD, we sequenced all 17 exons of VPS35 in 32 probands of presumed autosomal-dominant, late-onset familial PD and 35 normal controls. Meanwhile, we analyzed VPS35 Asp620Asn mutation in 512 PD patients. A total of 371 subjects without neurological disorders from the same region in China were set as a control group. We did not find any VPS35 coding region mutation in 32 familial PD patients. VPS35 Asp620Asn mutation was either not found in 480 PD patients. Our results suggested that VPS35 Asp620Asn may be not associated with PD in Chinese population.

Application of odor identification test in Parkinson's disease in China: A matched case-control study

As one of the most common non-motor symptoms in Parkinson's disease (PD), hyposmia is of great importance in establishing the early diagnosis of PD. To date, there are still no studies on the application of the 16-item odor identification test from Sniffin' Sticks (SS-16) in Chinese patients with PD. The aim of this study was to investigate the validity of SS-16 in Chinese PD patients (n=110) compared with age and gender matched controls (n=110), and to explore the associated factors with olfactory function in PD patients. The 16 odors in the original odor identification test were retained but some alternative descriptions were developed before applications. Mean identification scores in patients were significantly lower than in controls (7.3±2.8 VS. 11.6±2.0 P<0.01), with 66.4% of patients had an impairment of odor identification as evaluated by 95% confidential interval of the identification score of the control group. Receiver operating characteristic curves revealed 86% sensitivity and 81% specificity in separating PD and healthy controls with a cut-off value of 9.5. Multiple linear regression analysis revealed that autonomic dysfunction was a significant influential factor of odor identification scores in patients with PD. In conclusion, SS-16 provides a valid instrument for olfactory assessment in Chinese PD patients, and hyposmia may correlate with autonomic dysfunction in patients with PD.

Ten year survival and outcomes in a prospective cohort of new onset Chinese Parkinson's disease patients

ObjectiveThe 10 year outcomes and impact of motor and non-motor features on survival of a cohort of new onset Chinese Parkinson's disease (PD) patients were prospectively studied.MethodA cohort of new...

Analysis of the genotype of diacylglycerol kinase delta single-nucleotide polymorphisms in Parkinson disease in the Han Chinese population

Numerous Single-Nucleotide Polymorphisms (SNPs) of the Diacylglycerol Kinase Delta (DGKD) isoform 1 gene have been associated with Parkinson Disease (PD) in the genome-wide association studies of Caucasian population. This association has not been proven in the Han Chinese PD patients. This study included 376 unrelated Han Chinese PD patients from West China and 273 unrelated healthy controls from the same region. Five SNPs (rs2971859, rs1550532, rs2305539, rs2034762, and rs2242102) were genotyped using the Sequenom iPLEX Assay technology. No significant differences were observed in genotype frequencies and in the Minor Allele Frequency (MAF) in the five SNPs between PD patients and controls, early-onset PD and controls, late-onset PD and controls, and between early-onset and late-onset PD patients. The present study is the first to report on the lack of association of DGKD SNPs with PD in the Han Chinese population. More related studies involving larger numbers of participants are necessary to confirm the present finding.

Glucocerebrosidase L444P mutation confers genetic risk for Parkinson’s disease in central China

BackgroundMutations of the glucocerebrosidase (GBA) gene have reportedly been associated with Parkinson disease (PD) in various ethnic populations such as Singaporean, Japanese, Formosan, Canadian, American, Portuguese, Greek, Brazilian, British, Italian, Ashkenazi Jewish, southern and southwestern Chinese. The purpose of this study is to determine in central China whether or not the reported GBA mutations remain associated with PD.MethodsIn this project, we conducted a controlled study in a cohort of 208 central Chinese PD patients and 298 controls for three known GBA mutations (L444P, N370S and R120W).ResultsOur data reveals a significantly higher frequency of L444P mutation in GBA gene of PD cases (3.4%) compared with the controls (0.3%) (P = 0.007, OR = 10.34, 95% CI = 1.26 - 84.71). Specifically, the frequency of L444P mutation was higher in the late onset PD (LOPD) cases compared with that in control subjects. The N370S and R120W mutations were detected in neither the PD group nor the control subjects.ConclusionsOur observations demonstrated that the GBA L444P mutation confers genetic risk for PD, especially LOPD, among the population in the central China area.

Reliability and validity of PDQ-39: a quality-of-life measure for patients with PD in China

The syndromes of Parkinson's disease (PD) have impacts on health-related quality of life (HRQL). The 39-item Parkinson's disease Questionnaire (PDQ-39) was the first specific and a consistent instrument for the evaluation of HRQL in PD patients. To test the reliability and validity of Chinese version PDQ-39. Hundred and twenty-six PD without cognitive impairment were enrolled. The Chinese version of SF-36 was used to evaluate the congruent validity of PDQ-39 between related domains. Both PDQ-39 and SF-36 scales were fulfilled by the patients themselves. Five of eight subscales of PDQ-39 met the acceptable standards of reliability (Cronbach's α coefficient >0.80), while the other three subscales (cognition, communication, and bodily discomfort) failed to reach the above standards as reported by the others. All the item-to-subscale correlations (range: 0.457-0.887) met the minimal acceptable item convergent validity criterion of 0.40 (P < 0.001). Correlation between PDQ-39 subscales and scales of the SF-36 had high negative correlations with a range of -0.759 to -0.124. Four of them had significant negative correlations (P < 0.0001). The Chinese version of PDQ-39 is a reliable and valid instrument for Chinese PD patients. It is recommended as the most appropriate HRQL tool for PD.

Genetic Variants in the RAB7L1 and SLC41A1 Genes of the PARK16 Locus in Chinese Parkinson's Disease Patients

ABSTRACTWe performed direct DNA sequencing of the RAB7L1 and SLC41A1 genes within the PARK16 locus in 205 Chinese Parkinson's disease (PD) patients. Three novel heterozygous variants were identified in SLC41A1: c.436A > G (causing p.Lys146Glu), c.1440A > G (causing p.Pro480Pro), and c.552 + 50G > A. These three variants were not present in any of the 210 genetically unrelated healthy controls of the same ethnic origin. No changes were identified in the RAB7L1 gene. Additionally, for the eight core PARK16 SNPs, no significant difference in allele or genotype frequencies was observed between PD patients and controls. Further analysis is required to determine the role of genes within the PARK16 locus in development of PD.

A validation study of the Chinese wearing off questionnaire 9-symptom for Parkinson's disease

Objective Development of wearing off (WO) often goes unnoticed for both patients with Parkinson's disease (PD) and physicians due to the complexity of this phenomenon. A brief 9-symptom WO questionnaire (WOQ-9) was recently found to be highly sensitive in its detection. We aimed to validate a Chinese version WOQ-9 (CWOQ-9) among Chinese patients with PD. Methods We recruited 101 literate Chinese PD patients among 4 different neurology or movement disorders clinics in Hong Kong to participate in this study by completing the CWOQ-9. Clinical judgment by the specialists was considered the gold standard for diagnosing WO. Results The mean age (±SD) of the patients was 61 (±9) years and 35 (34.7%) of them were female. The disease duration was 7.4 (±5.4) years and 69 (68.3%) of them were diagnosed clinically to have WO by the specialists. The positive and negative predictive values, sensitivity and specificity of CWOQ-9 were 86%, 71%, 87%, and 69% respectively. The area under curve (AUC) was 0.78 ( p < 0.001). Conclusion This simple patient questionnaire is a valid tool for the detection of WO among Chinese PD patients.

PITX3 gene polymorphism is associated with Parkinson's disease in Chinese population

Genetic variants of PITX3 gene have been reported to be associated with Parkinson's disease (PD) in several populations. We conducted a case-control study and genotyped the three SNPs of PITX3 gene: rs2281983, rs4919621 and rs3758549 in 512 mainland Chinese PD patients and 506 healthy controls. Our findings show that the PITX3 gene rs3758549 polymorphism is associated with PD ( p = 0.02). Moreover, the difference between late onset PD patients and healthy controls is stronger ( p = 0.007). There is no statistical difference in genotype or allele frequencies of rs2281983 or rs4919621 variant in PITX3 gene between sporadic PD (SPD) group and healthy control group in our study. To assess the possible role of the PITX3 gene rs3758549 polymorphism in PD, we conducted a meta-analysis on the topic. The results of meta-analysis further support that the PITX3 gene rs3758549 polymorphism is associated with PD: Z = 3.09, p = 0.002, OR = 0.89. These findings suggest that the PITX3 gene rs3758549 polymorphism may increase the susceptibility of PD.

Genetic variations of Omi/HTRA2 in Chinese patients with Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder, with approximately 5–10% of PD cases being linked to genetic factors. The Htra serine peptidase 2 (HTRA2) gene, also known as Omi, was found to be associated with PD in a cohort of German PD patients. However, subsequent studies have indicated that some variants of Omi/HTRA2 may not be related to PD. In order to investigate whether the Omi/HTRA2 gene is related to PD in Han Chinese PD patients, molecular analysis for the Omi/HTRA2 gene was performed in 404 Chinese PD patients and 504 normal individuals. Our present study revealed 2 novel variations. The IVS5+29T>A variant may be a risk factor for PD (P<0.05), while the c.G77A variant might be a pathogenic mutation. However, the findings need to be validated in a larger population using further functional studies.

Smoking, genes encoding dopamine pathway and risk for Parkinson's disease

Smoking has been reported to be inversely associated with Parkinson's disease (PD) in many studies, but a recent study in China found that smoking increased the risk of PD. Variants in genes associated with dopamine metabolism found to increase the risk for PD have also been associated with smoking behavior. To investigate the association between smoking and PD in a Chinese population and determine whether the genetic variants of genes involved in dopamine metabolism influence the relationship between smoking and risk for PD. Chinese PD patients were recruited from Xuanwu Hospital. Controls were sampled from community. Detailed information on life-long smoking behavior was collected by face-to-face interview. Genotypes were determined for SLC6A3 VNTR, COMT Val108/158Met and MAO-B intron13 A/G polymorphisms by PCR-RFLP, DHPLC and sequencing. Chi-square and logistic regression model were used in the analysis. 176 PD cases and 354 controls were enrolled in this study. 23.9% cases are smokers, compared to 48.0% in controls. Ever smoking is inversely associated with PD (odds ratio = 0.14, 95% CI 0.08–0.26, adjusted for age and gender). None of the above-mentioned genetic polymorphisms was associated with PD risk or smoking. When each variant was included in the logistic regression model, the inverse association between smoking and PD remained the same, and the interactions between smoking and variants were not significant in the model. Our data support a reduction of PD risk associated with smoking in a Chinese population. These variants of genes associated with DA uptake and metabolism do not affect the inverse association between smoking and PD.

Glucocerebrosidase Gene L444P mutation is a risk factor for Parkinson's disease in Chinese population

An association between mutations in the glucocerebrosidase (GBA) gene and Parkinson's disease (PD) has been reported in several populations. We searched for four common GBA mutations (L444P, F213I, R353W, and N370S) in 402 Chinese PD patients and 413 age- and sex-matched controls. In the PD cohort, 11 patients were found carrying a heterozygous GBA mutation and all of them had the L444P mutation. Heterozygous GBA mutations were detected none in controls. The GBA gene L444P mutation was detected at a significantly higher frequency among PD patients (11/402 = 2.74%), when compared with the control group (0/413): P = 0.0007. To evaluate the possible role of the GBA gene L444P mutation in PD in Ashkenazi Jewish and non-Jewish populations, we conducted a meta-analysis on the topic. In the Chinese population, the GBA gene L444P mutation was detected at a significantly higher frequency among PD patients, when compared with the control group: Z = 3.83, P = 0.0001, OR = 8.42, confidence interval = 95%, 2.83-25.06. In the non-Jewish populations, the difference was obviously significant: Z = 5.76, P < 0.00001, OR = 8.82, confidence interval = 95%, 4.21-18.48. The results suggest that the GBA gene L444P mutation appears to be a risk factor for PD in Chinese population.

SNP rs7684318 of the α-synuclein gene is associated with Parkinson's disease in the Han Chinese population

Mutations in the α-synuclein (SNCA) gene have been shown to be responsible for a rare familial form of Parkinson's disease (PD). Furthermore, polymorphic variants in multiple regions of the gene have been associated with susceptibility to idiopathic PD in different populations. Previous studies in Japanese have found a strong association between idiopathic PD and the single-nucleotide polymorphism (SNP) rs7684318, which is located within an intron of the SNCA gene. Our aim was to verify these findings and to further explore the nature of the association in a subset of Han Chinese PD patients. A case–control study of the SNP rs7684318, comprising 332 PD patients and 300 healthy controls, was carried out in Han Chinese populations from two centers in mainland China. The rs7684318 polymorphism was determined by PCR-restriction fragment length polymorphism (PCR-RFLP) analysis. The SNP rs7684318 of the SNCA gene showed a strong association with PD ( P < 0.01). Among our PD patients, mean age at disease onset and gender did not differ significantly between rs7684318 carriers and non-carriers. Our findings suggested that the SNP rs7684318 (T>C) transition of the SNCA gene contributes to PD susceptibility in Chinese Han population, which is consistent with the earlier study form Japan.