Clinical characteristics of Parkinson’s disease among Jewish Ethnic groups in Israel

Test, track, treat using wearable sensors for management of Parkinson's disease: 12‑month prospective observational United Arab Emirates study using Parkinson's Kinetograph (EmPark-PKG Study)

Parkinson's disease (PD) is a progressive neurodegenerative disorder marked by both motor and non-motor symptoms that necessitate ongoing clinical evaluation and medication adjustments. Home-based wearable sensor monitoring offers a detailed and continuous record of patient symptoms, potentially enhancing disease management. The EmPark-PKG study aims to evaluate the effectiveness of the Parkinson's KinetoGraph (PKG), a wearable sensor device, in monitoring and tracking the progression of motor symptoms over 12 months in Emirati and non-Emirati PD patients. Fifty PD patients (32% Emirati, 68% non-Emirati) were assessed at baseline and a 12-month follow-up. Clinical evaluations included levodopa equivalent daily dosage (LEDD) and motor and non-motor assessments. Concurrently, the PKG provided metrics such as bradykinesia score (BKS) and dyskinesia score (DKS). Statistical analyses were conducted to determine changes from baseline to six months, differences between Emirati and non-Emirati groups, and correlations between PKG metrics and clinical assessments. Significant reductions in LEDD and improvements in both motor and non-motor scores were observed from baseline to six months (p < 0.05). PKG-guided medication adjustments were associated with enhanced motor and non-motor outcomes (p < 0.05). Specifically, non-Emirati patients exhibited a significant reduction in LEDD (Z = - 2.010, p = 0.044), whereas Emirati patients did not (Z = - 0.468, p = 0.640). Both groups showed significant improvements in motor scale scores and motor complication scores. Spearman correlation analysis revealed strong relationships between PKG metrics and subjective clinical assessments (p < 0.001). The EmPark-PKG study demonstrates the potential benefits of remote PKG monitoring for personalised motor symptom management in PD. PKG supports a stepped care paradigm by enabling bespoke medication titration based on objective data, facilitating tailored and effective patient care.

Race and ethnicity matter! Moving Parkinson's risk research towards diversity and inclusiveness

Parkinson's disease (PD) is a prevalent neurodegenerative disorder that shows considerable heterogeneity of risk factors however, the degree to which race/ethnicity has been actively pursued in PD risk research is unknown. We examined PD literature from 2000-24 and found that less than half accounted for race/ethnicity and only 4.8% of n = 1142 articles included ethno-racial factors as an integral part of the analysis. This demonstrates that race/ethnicity has been critically understudied in PD and further studies that examine ethno-racial contributions to risk for PD are warranted.

Prevalence of ten LRRK2 variants in Parkinson's disease: A comprehensive review

INTRODUCTION

Variants in the leucine-rich repeat kinase 2 gene (LRRK2) are risk factors for Parkinson's disease (PD), but their prevalence varies geographically, reflecting the locations of founder events and dispersion of founders' descendants.

METHODS

A comprehensive literature review was conducted to identify studies providing prevalence estimates for any of ten variants in LRRK2 (G2019S, R1441C, R1441G, R1441H, I2020T, N1437H, Y1699C, S1761R, G2385R, R1628P) among individuals with PD globally. We calculated crude country-specific variant prevalence estimates and, when possible, adjusted estimates for ethno-racial composition. For clinic-based studies, probands were used over other familial cases, whereas for population-based studies, all PD cases were used.

RESULTS

The analysis included 161 articles from 52 countries yielding 581 prevalence estimates across the ten variants. G2019S was the most common variant, exceeding 1.0% in 26 of 51 countries with estimates. The other variants were far less common. G2385R and R1628P were observed almost exclusively in East Asian countries, where they were found in ∼5-10% of cases. All prevalence estimates adjusted for ethno-racial composition were lower than their unadjusted counterparts, although data permitting this adjustment was only available for six countries.

CONCLUSIONS

Except for G2019S, the LRRK2 variants covered in this review were uncommon in most countries studied. However, there were countries with higher prevalence for some variants, reflecting the uneven geographic distribution of LRRK2 variants. The fact that ethno-racial group‒adjusted estimates were lower than crude estimates suggests that estimates derived largely from clinic-based studies may overstate the true prevalence of some LRRK2 variants in PD.

Does Ethnicity Influence Recruitment into Clinical Trials of Parkinson's Disease?

BACKGROUND

Lack of participation of black and minority ethnic communities (BAME) in registered clinical trials is a concern as data emerging from these studies are used to licence new drugs or other interventions, even though findings made in such selected study populations have limited external validity in the aforesaid ethnic groups.

OBJECTIVE

We used Parkinson's disease (PD), the fastest rising neurodegenerative disorder in the world, as an exemplar condition to test our hypothesis that participants from BAME communities are underrepresented in clinical trials.

METHODS

A systematic search of clinical trials registered on a Clinicaltrials.gov database which queried for PD with racial distribution data from 2017 to 2021.

RESULTS

Out of 266 trials considered, 54 trials were published in peer reviewed journals. Among these, only 23 (42.65%) publications reported data regarding the racial distribution of the participants. Out of these, five studies involved mixed racial participation and two trials included black subjects.

CONCLUSION

We found that inclusion of under-represented BAME groups in recently published clinical trials is low, at only 21.57%, and is not even considered in most studies. Out of the reviewed trials, only 5 (21.75%) studies reported detailed demographic categories with black minorities enrolment. This constitutes a severe under-representation when compared to the proportion of Black or African American in the UK population (3%). Results of this study identified the need for better reporting of racial composition in clinical trials. We strongly recommend that future studies should consider ethnicity and other issues around diversity when designing and implementing the clinical trials, not only in the PD field but also beyond.

Ethnic Variation in the Manifestation of Parkinson's Disease: A Narrative Review

The global prevalence of Parkinson's disease is increasing, yet the characteristics, risk factors and genetics of PD in Black, Asian and Hispanic populations is little understood. In this paper we review the published literature on clinical variation in the symptoms and signs of Parkinson's disease in different ethnic groups and responses to treatment. We included any study that sampled patients with Parkinson's disease from distinct ethnic backgrounds. We conclude that whilst there is little published evidence for ethnic variation in the clinical features of Parkinson's disease, there are substantial limitations and gaps in the current literature, which mean that the evidence does necessarily not fit with clinical observation. Possible explanations for expected differences in manifestation include genetic determinants, the co-existence of cerebrovascular disease and/or Alzheimer's disease pathology, healthcare inequalities and socio-cultural factors.

Parkinson's Disease in the Middle East, North Africa, and South Asia: Consensus from the International Parkinson and Movement Disorder Society Task Force for the Middle East

BACKGROUND

Understanding the regional needs and available healthcare resources to treat Parkinson's disease (PD) is essential to plan appropriate future priorities. The International Parkinson and Movement Disorder Society (MDS) Task Force for the Middle East was established to raise awareness and promote education across the region on PD and other movement disorders. Broadly, the task force encompasses the countries of the Middle East but has included North Africa and South Asia as well (MENASA).

OBJECTIVE

To create a list of needs and priorities in the advancement of PD in MENASA countries based on consensuses generated by the MDS task force for the Middle East.

METHODS

A Strengths Weaknesses-Opportunities-Threats (SWOT) analysis was conducted by the task force members to generate consensus about PD care this region.

RESULTS

Eight overarching principles emerged for the consensus statement on current needs: more movement disorders specialists, multidisciplinary care, accurate epidemiologic data, educational programs, availability of drugs, and availability of more advanced therapy, enhanced health care resources and infrastructure, and greater levels of awareness within the general population and among health care professionals.

CONCLUSION

This pilot study sheds light on unmet needs for providing care to people with PD in the MENASA region. These data offer directions on priorities to increase awareness of PD, to develop better infrastructure for research and management of PD, to foster healthcare policy discussions for PD and to provide educational opportunities within these countries.

Non-Ashkenazi Jewish Origin is Associated with Early Onset Alzheimer's Disease

Early-onset Alzheimer's disease (EOAD) accounts for 1-5% of Alzheimer's disease cases and is associated with specific ethnicities. It has been our impression that non-Ashkenazi Jews have a higher rate of EOAD and we therefore explored this hypothesis. We performed a retrospective case control study of EOAD cases referred to our cognitive neurology clinic between January 1999 and December 2016. Patients (n = 129) were compared to age- and geographically-matched controls generated from the Second Israeli National Health Survey (n = 1,811). Data on country of origin, education, dementia family history, depression, and vascular risk factors were compared between the groups. The association of non-Ashkenazi Jewish heritage and country of origin with EOAD was calculated using a logistic multivariate regression model. The EOAD group's mean age was 59.6±4.1 years, with a female predominance (64.3%). The EOAD group had a higher percentage of individuals of non-Ashkenazi Jewish origin (64.3% versus 51.4%, p = 0.003) and of Yemenite descent in particular (16.28% versus 6.24%, p < 0.001). On multiple logistic regression analysis, Yemenite Jewish origin was an independently associated with EOAD (OR 2.54, 95% CI 1.4-4.8). There were no significant differences in parameters between non-Ashkenazi and Ashkenazi Jews. Only 4.6% of EOAD cases had a positive EOAD family history. In conclusion, EOAD is over-represented among non-Ashkenazi Jews. Yemenite origin is independently associated with EOAD and the majority of patients with EOAD have no family history of Alzheimer's disease. Further evaluation with genetic studies is warranted.

Pain in Extrapyramidal Neurodegenerative Diseases

OBJECTIVE

Pain is one of the most common nonmotor symptoms of Parkinson disease (PD) and other Parkinson plus syndromes, with a major effect on quality of life. The aims of the study were to examine the prevalence and characteristics of pain in PD and other Parkinson plus syndromes and patient use and response to pain medications.

METHODS

The cohort consisted of 371 patients: 300 (81%) with PD and 71 (19%) with Parkinson plus syndromes. Data on clinical parameters and pain were collected by questionnaire. Disease severity was measured with the Unified PD Rating Scale for patients with PD.

RESULTS

Pain was reported by 277 patients (74%): 241 with PD and 36 with Parkinson plus syndromes. The prevalence of pain was significantly higher in the patients with PD than in the patients with Parkinson plus syndromes (80% vs. 50%, P<0.001) and higher in patients with synucleinopathies than in patients with tauopathies (70% vs. 40%, P<0.001). In the synucleinopathies, the most common pain was central pain (32%), whereas in the tauopathies only 4% of patients had central pain. Anti-Parkinson treatment relieved the pain in 21% of the patients with PD. Only 114 patients (48%) who experienced pain were treated with pain medications. The most beneficial analgesics were nonsteroidal anti-inflammatory drugs and medical cannabis.

CONCLUSION

Pain is prevalent among patients with PD and Parkinsonian plus syndromes. Pain relief can be achieved by more intensive anti-Parkinson medications or pain medications.

Leucine-Rich Repeat Kinase (LRRK2) Genetics and Parkinson's Disease

The discovery of LRRK2 mutations as a cause of Parkinson's disease (PD), including the sporadic late-onset form, established the decisive role of genetics in the field of PD research. Among LRRK2 mutations, the G2019S, mostly lying in a haplotype originating from a common Middle Eastern ancestor, has been identified in different populations worldwide. The G2385R and R1628P variants represent validated risk factors for PD in Asian populations. Here, we describe in detail the origin, the present worldwide epidemiology, and the penetrance of LRRK2 mutations. Furthermore, this chapter aims to characterize other definitely/probably pathogenic mutations and risk variants of LRRK2. Finally, we provide some general guidelines for a LRRK2 genetic testing and counseling. In summary, LRRK2 discovery revolutionized the understanding of PD etiology and laid the foundation for a promising future of genetics in PD research.

Exploring determinants of progression in Parkinson's disease. Is there a difference among Jewish ethnic groups?

INTRODUCTION

Parkinson's disease (PD) displays an individually variable rate of progression, of which the underlying mechanisms are largely unknown, but may involve genetic factors. In this study, we aimed to explore the effect of ethnic origin on PD progression rate in Israeli Jews, as expressed by time from onset until reaching Hoehn and Yahr stage 3 (HY3).

METHODS

Consecutive patients with PD followed bi-annually at the Movement Disorders Institute at Sheba Medical Center, were included. Demographic data and clinical information, including age at PD onset (AO), H&Y staging, and family history of PD, were collected. Ethnicity was determined based on the parents' origin and was categorized as Ashkenazi Jews (AJ), Yemenite Jews (YJ), North African Jews (NAJ) and Oriental Jews (OJ) excluding YJ. Associations between the above variables and the time to HY3 were determined using Cox proportional hazards model. Survival curves were derived from the model.

RESULTS

Of 707 patients [430 males, AJ: 458, YJ: 37, NAJ: 75 and OJ: 137] included in the analysis, 343 had reached HY3. In a multivariate analysis, a longer time to HY3 was significantly associated with a younger AO (HR = 1.07, p < 0.001). YJ showed a significantly shorter time to HY3 compared to AJ and OJ, but not compared to NAJ. Time to HY3 was significantly shorter for NAJ than for OJ.

CONCLUSION

Jewish PD patients of Yemenite and North African origin may have a more rapid progression of PD, compared to those of Ashkenazi and Oriental origin, suggesting distinctive genetic influences.

Genetic characteristics of leucine-rich repeat kinase 2 (LRRK2) associated Parkinson's disease

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the progressive and selective degeneration of nigrostriatal dopaminergic neurons. The discovery of at least six PD-causing genes in predominantly early-onset forms of the disorder has cemented a genetic component to the etiology. Notably, the discovery of mutations in the LRRK2 gene in patients presenting with typical 'sporadic' PD with ages at onset in their sixties and seventies has shifted paradigms in the field of PD research. The G2019S mutation in LRRK2 has been found in diverse populations worldwide and usually resides on a common haplotype revealing that many of these individuals share a common ancestor, probably of Middle Eastern origin. The only validated coding susceptibility alleles for PD, G2385R and R1628P, are both in this gene but to date have been found exclusively in Asian populations. Concomitant with genetic testing for PD is the need for appropriate and informed genetic counseling. Families of patients with LRRK2 mutations and susceptibility alleles need to be informed about the current lack of disease preventative strategies and the implications surrounding incomplete penetrance. In summary, single-handedly LRRK2 has had a major impact on the field of PD research and the findings have been of interest to both clinicians and scientists. We anticipate that other genes of such major impact exist for PD and look forward to their discovery.

What genetics tells us about the causes and mechanisms of Parkinson's disease

Parkinson's disease (PD) is a common motor disorder of mysterious etiology. It is due to the progressive degeneration of the dopaminergic neurons of the substantia nigra and is accompanied by the appearance of intraneuronal inclusions enriched in α-synuclein, the Lewy bodies. It is becoming increasingly clear that genetic factors contribute to its complex pathogenesis. Over the past decade, the genetic basis of rare PD forms with Mendelian inheritance, representing no more than 10% of the cases, has been investigated. More than 16 loci and 11 associated genes have been identified so far; genome-wide association studies have provided convincing evidence that polymorphic variants in these genes contribute to sporadic PD. The knowledge acquired of the functions of their protein products has revealed pathways of neurodegeneration that may be shared between inherited and sporadic PD. An impressive set of data in different model systems strongly suggest that mitochondrial dysfunction plays a central role in clinically similar, early-onset autosomal recessive PD forms caused by parkin and PINK1, and possibly DJ-1 gene mutations. In contrast, α-synuclein accumulation in Lewy bodies defines a spectrum of disorders ranging from typical late-onset PD to PD dementia and including sporadic and autosomal dominant PD forms due to mutations in SCNA and LRRK2. However, the pathological role of Lewy bodies remains uncertain, as they may or may not be present in PD forms with one and the same LRRK2 mutation. Impairment of autophagy-based protein/organelle degradation pathways is emerging as a possible unifying but still fragile pathogenic scenario in PD. Strengthening these discoveries and finding other convergence points by identifying new genes responsible for Mendelian forms of PD and exploring their functions and relationships are the main challenges of the next decade. It is also the way to follow to open new promising avenues of neuroprotective treatment for this devastating disorder.

The LRRK2 G2019S mutation as the cause of Parkinson's disease in Ashkenazi Jews

Mutations in the leucine rich repeat kinase 2 gene (LRRK2) are recognized as the most common cause of genetic Parkinsonism to date. The G2019S mutation has been implicated as an important determinant of Parkinson's disease (PD) in both Ashkenazi Jewish and North African Arab populations with carrier frequency of 29.7% among familial and 6% in sporadic Ashkenazi Jewish PD cases. PD patients with the G2019S mutation display similar clinical characteristics to patients with sporadic PD. While the function of the LRRK2 protein has yet to be fully determined, its distribution coincides with brain areas most affected by PD. The G2019S mutation is believed to be responsible for up-regulation of LRRK2 kinase activity, which may ultimately play a role in neuronal loss. The utility of LRRK2 G2019S screening in family members of Ashkenazi PD patients is discussed. LRRK2 G2019S mutation carriers without PD may be an ideal population for the study of possible neuroprotective strategies as they become available, and for furthering the understanding of the pathogenesis and long-term clinical outcomes of the disease.

The leucine rich repeat kinase 2 (LRRK2) G2019S substitution mutation. Association with Parkinson disease, malignant melanoma and prevalence in ethnic groups in Israel

BACKGROUND

A single missense mutation (G2019S) in the leucine rich repeat kinase 2 (LRRK2) gene has been reported to be prevalent among Ashkenazi Jewish patients with Parkinson disease (PD). An association between malignant melanoma (MM) and PD was also recently reported. The nature of this association is still elusive.

OBJECTIVE

To evaluate the rate of the G2019S(*) LRKK2 mutation among ethnically diverse, Jewish PD patients, MM patients, and Ashkenazi, Iraqi and Moroccan healthy controls.

PATIENTS AND METHODS

Overall, 242 Jewish PD patients (155 Ashkenazim and 7 of mixed origin) and 169 Jewish MM patients (142 Ashkenazim) were genotyped for the G2019S mutation. In addition, 900 healthy ethnic Jewish controls (300 Ashkenazim, 300 Moroccans and 300 Iraqis) were similarly analyzed. Genotyping was performed using PCR amplification followed by restriction digest and gel electrophoresis. Statistical analysis was done using the Chi square test.

RESULTS

Overall 19/242 (7.9 %) of the PD patients (16/155 of Ashkenazim, 10.3 %; 3/87 of non-Ashkenazim, 3.4 %) harbored the G2019S LRKK2 mutation. The age at diagnosis of PD in mutation carriers was 60.6 +/- 10.9 years compared with an age at diagnosis of 61.1 +/- 13.4 years in non-carriers (p = 0.87). Nine of 38 familial Ashkenazi PD patients (23.68 %) carried the mutation, as did 2/169 MM patients (1.2 %; 2/142, 1.4 % of the Ashkenazim). A single mutation carrier of Ashkenazi origin was detected among 900 controls (0.3 % of the Ashkenazi controls).

CONCLUSION

The G2019S*LRKK2 mutation is significantly more prevalent in Ashkenazi PD patients than in controls (p = 1 x 10(-6)), it is less commonly detected in non-Ashkenazi affected individuals, and its contribution to MM predisposition in Jewish individuals needs to be explored further.