Psychometric properties of Arabic-translated-related quality of life scales for people with parkinson disease: a scoping review

BACKGROUND

Parkinson's disease (PD) substantially contributes to poor functional outcomes, loss in productivity, and poor health-related quality of life (HRQoL). Despite the existence of various scales, there is a notable gap in existing HRQoL reviews with regard to the availability of Arabic validated scales. As a response to this gap, the aim of our scoping review is to identify validated scales, focusing on their psychometric validation procedures, to contribute valuable insights to the understanding of HRQoL among the Arabic-speaking people with PD.

METHODS

A scoping review was conducted at the end of December 2022, using the Medline and Embase databases. The focus of this review was on examining the psychometric properties and validation procedures of included scales. Articles were included in the full-text screening process if they focused on people with PD of any age, included a scale measuring HRQoL in Arabic, and were written in English, French, or Arabic.

RESULTS

After applying inclusion/exclusion criteria, 10 studies were selected to analyze HRQoL scales validated in people with PD. However, the PDQ-39 is the only HRQol PD specific scales validated in the Arabic language. Five studies validated in people with PD were identified in the context of instrument validation (3 generic, 1 specific validated in 2 studies).

CONCLUSION

There are several HRQoL measurement scales for people with PD. However, only one specific HRQoL instrument has been validated in Arabic for people with PD. For the remaining instruments identified they were just used in people with PD without being validated in this population.

Parkinson's disease research in Morocco: a review

Aim: To quantify and provide an overview on the scientific productivity made by Moroccan academics in the research on Parkinson's disease (PD) and parkinsonism. Materials & methods: Scientific articles, in either English or French, were gathered from published literature in three recognized databases: PubMed, ScienceDirect and Scopus. Results: We identified 95 published papers from which 39 articles have been extracted after removing inadequate publications and duplications between databases. All articles were published between 2006 and 2021. The selected articles were subdivided into five categories. Conclusion: The Moroccan academia is presently facing a low productivity issues and a lack of research laboratories focusing on PD research. We anticipate that providing more budgetary funds will significantly improve the productivity of PD research.

Recalling the pathology of Parkinson's disease; lacking exact figure of prevalence and genetic evidence in Asia with an alarming outcome: A time to step-up

Parkinson's disease (PD) is the second most common and progressive neurodegenerative disease globally, with major symptoms like bradykinesia, impaired posture, and tremor. Several genetic and environmental factors have been identified but elucidating the main factors have been challenging due to the disease's complex nature. Diagnosis, prognosis, and management of such diseases are challenging and require effective targeted attention in developing countries. Recently, PD is growing rapidly in many crowded Asian countries as an alarming threat with inadequate knowledge of its prevalence, genetic architecture, and geographic distribution. This study gave an in-depth overview of the prevalence, incidence and genomic/genetics studies published so far in the Asian population. To the best of our knowledge, PD has increased significantly in several Asian countries, including China, South Korea, Japan, Thailand, and Israel over the past few years, requiring a greater level of care and attention. Genetic screening of families with PD at national levels and establishing an official database of PD cases are essential to get a comprehensive and conclusive view of the exact prevalence and genetic diversity of PD in the Asian population to properly manage and treat the disease.

Dementia with Lewy bodies in first-generation immigrants in a European memory clinic

We wanted to explore possible differences in disease presentation, frequency, and age of onset of dementia with Lewy bodies (DLB) between first-generation immigrants (FGI) and patients born in Belgium (PBIB). We conducted a retrospective study on all patients of our Memory Clinic between June 1, 2010 and January 31, 2020. A synucleinopathy was diagnosed in 150 of 2702 patients (5.5%): 91 received a diagnosis of DLB (3.4%). FGI were two times more likely to receive a diagnosis of DLB, due to a higher prevalence in North-Africans and Latin-Americans. Visual hallucinations were less frequent in North-Africans than in other immigrants. FGI were younger than PBIB and reported more often parasomnia. Our data suggest a higher risk for DLB in certain immigrant groups. Especially for North-African patients, a genetic factor can be suspected, namely mutations in Leucine-rich repeat kinase 2 (LRRK2). Memory clinics with a high rate of FGI may provide interesting data and insights into the prevalence of DLB, genetic and environmental differences.

LCIG in treatment of non-motor symptoms in advanced Parkinson's disease: Review of literature

BACKGROUND

For managing nonmotor symptoms (NMS) in advanced Parkinson's disease (PD), levodopa-carbidopa intestinal gel (LCIG) infusion is of interest as it shows lesser plasma fluctuations of both drugs as compared to oral levodopa-carbidopa (LC).

OBJECTIVES

To highlight LCIG effect in NMS among advanced PD patients and appraise the currently available literature.

METHODS

PubMed screening (till 2020) of 184 articles was done, of which 51 were selected. Among them, 23 original articles relevant to the research question were included, of which 6 were then excluded after careful reading of full articles. The 17 relevant studies of the review provide Grade C level of evidence of efficacy.

RESULTS

LCIG is beneficial in improving or relieving various NMS especially (mood, cognition/memory, sleep, gastrointestinal symptoms, urinary symptoms, and quality of life questionnaires) in patients with advanced PD. Amelioration of motor functions or direct relations may lead to improvement in NMS PD patients using LCIG. Adverse events noted in patients treated with LCIG include pneumoperitoneum, abdominal pain, stoma infection, reversible peripheral neuropathy, local tube problems, impulse control disorder, and weight loss. Serious adverse events were mostly found to be unrelated to LCIG.

CONCLUSIONS

LCIG provides an uninterrupted intestinal levodopa infusion by percutaneous endoscopic gastrojejunostomy (PEG-J). It effectively decreases plasma fluctuations of levodopa and reduces motor instability and NMS burden in advanced PD. However, adequate dose modification and individualization of therapy are essential for optimal effect.

Gender and Age Difference in Clinical Features and severity of Parkinson’s Disease: A Cross-Sectional Study in Southern Morocco

Background: Parkinson’s disease is the second most frequently reported neurodegenerative disease, behind Alzheimer’s disease. In Morocco, enough information are not available about its prevalence, progression, and characteristics, particularly in Southern regions of the country. Objectives: The current study aimed to investigate gender and age differences in the sociodemographic and clinical profile of Parkinson’s disease patients in southern Morocco. Methods: A cross-sectional descriptive study was conducted on a selected cohort of 180 patients, previously diagnosed with Parkinson’s. Results: The results showed that the onset of the disease was earlier in females compared to males. Besides, we found that the prevalence of rigidity symptoms was slightly higher in younger patients and in patients aged 61 to 70 years old, at the onset of the disease. Importantly, the results showed that the initial symptoms of males were different than females. According to the Hoehn and Yahr scale, the majority (82.6%) of patients of both genders were in the early stage of the disease. Additional statistical analyses, confirmed that the severity of the disease was strongly related to gender (P = 0.02). Conclusions: The findings confirmed that males and females had different clinical motor characteristics in the initial symptoms and progression of Parkinson’s disease. Nevertheless, experimental studies should be conducted to arrive at a real understanding of what underlies these differences.

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.

Dementia-Related Functional Disability in Moderate to Advanced Parkinson's Disease: Assessment Using the World Health Organization Disability Assessment Schedule 2.0

Dementia is a common nonmotor condition among people with moderate or advanced Parkinson’s disease (PD). Undoubtedly, profound motor symptoms cause remarkable impairment in daily activities; however, dementia-related disabilities have not been thoroughly investigated, especially not with consideration of differences according to sex. The present study used the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) to compare the functional disability between men and women with PD (PwP) with and without dementia. This study employed a registry of disability evaluation and functional assessment using the Taiwan Data Bank of Persons with Disability between July 2012 and October 2018. To investigate dementia-related disability in PwP, 1:1 matching by age and Hoehn-Yahr stage was conducted, which resulted in the inclusion of 1605 study participants in each group. The present study demonstrated that among the six major domains of WHODAS 2.0, the section of “Getting alone with others” was significantly worse in both genders of PwP with dementia; however, a greater disability in fulfilling activities of daily living was only noted in male PwP with dementia but not in their female counterparts. Neither the inability to provide self-care nor participation were significantly different between the sexes. Our findings suggested that deteriorating social relationships were a dementia-related disability in all PwP at the moderate and advanced disease stages. Regarding the performance of activities of daily living, deterioration was related to dementia only in male PwP. Such disabilities could indicate cognitive impairment in people with moderate or advanced PD and could be used as an indicator for the early detection of dementia in PwP by healthcare professionals through the easier functional assessment of the WHODAS 2.0.

K-variant BCHE and pesticide exposure: Gene-environment interactions in a case-control study of Parkinson's disease in Egypt

Pesticide exposure is associated with increased risk of Parkinson’s disease (PD). We investigated in Egypt whether common variants in genes involved in pesticide detoxification or transport might modify the risk of PD evoked by pesticide exposure. We recruited 416 PD patients and 445 controls. Information on environmental factors was collected by questionnaire-based structured interviews. Candidate single-nucleotide polymorphisms (SNPs) in 15 pesticide-related genes were genotyped. We analyzed the influence of environmental factors and SNPs as well as the interaction of pesticide exposure and SNPs on the risk of PD. The risk of PD was reduced by coffee consumption [OR = 0.63, 95% CI: 0.43–0.90, P = 0.013] and increased by pesticide exposure [OR = 7.09, 95% CI: 1.12–44.01, P = 0.036]. The SNP rs1126680 in the butyrylcholinesterase gene BCHE reduced the risk of PD irrespective of pesticide exposure [OR = 0.38, 95% CI: 0.20–0.70, P = 0.002]. The SNP rs1803274, defining K-variant BCHE, interacted significantly with pesticide exposure (P = 0.007) and increased the risk of PD only in pesticide-exposed individuals [OR = 2.49, 95% CI: 1.50–4.19, P = 0.0005]. The K-variant BCHE reduces serum activity of butyrylcholinesterase, a known bioscavenger for pesticides. Individuals with K-variant BCHE appear to have an increased risk for PD when exposed to pesticides.

Non-Motor Symptoms as Predictors of Quality of Life in Egyptian Patients With Parkinson's Disease: A Cross-Sectional Study Using a Culturally Adapted 39-Item Parkinson's Disease Questionnaire

Objective

The prevalence of non-motor symptoms (NMSs) and their impact on health-related quality of life (HRQoL) in Parkinson's disease (PD) has been reported inconsistently among different populations. In this study, we aimed to investigate the NMSs and HRQoL profiles and their correlation in Egyptian PD patients, using a culturally adapted Arabic version of the 39-item Parkinson's disease questionnaire (PDQ-39).

Methods

Ninety-seven PD patients were rated using the unified Parkinson's disease rating scale (UPDRS), the non-motor symptoms scales (NMSS), Beck depression inventory (BDI), and the Arabic version of PDQ-39. We used the Spearman's rank correlation and multiple linear regression analyses to evaluate the relationship between NMSs domains and HRQoL dimensions.

Results

Fatigue/sleep (91.3%) and mood/cognitive disturbances (87%) were the most frequently and severely affected NMSS domains. Other common NMSs included urinary (75.9%), memory/attention (72.4%), gastrointestinal (67.8%), and cardiovascular problems (64.8%). The total NMSS scores were positively correlated with UPDRS I, II, and III scores. Depression was prevalent in 76.7% of PD patients. Moreover, all enrolled PD patients reported impairment in different HRQoL dimensions, especially mobility (98.9%), activities of daily living (97.8%), and emotional well-being (95.5%). The summary index of PDQ-39 was correlated to the total NMSS, UPDRS-I, UPDRS-II Off, UPDRS-III (Off and On states), and BDI scores.

Conclusion

This study showed the high prevalence of NMSs and the value of NMSS and BDI scores as predictors of HRQoL in Egyptian PD patients. Therefore, characterizing the NMSs profile is essential for tailoring management strategies for PD patients.

Dementia in Eastern Mediterranean countries: A systematic review

Globally, there is an increase in the older population, whose lives are affected by local cultural norms. In Eastern Mediterranean countries, dementia is conventionally hidden from view with few dedicated services or recognition for diagnosis. The aim of this systematic review is to explore the limited literature on dementia and cognitive impairment among older people in Eastern Mediterranean countries to present an evaluation of current practices and to consolidate knowledge for future planning. Thirty-three studies were identified for inclusion in the review, and four themes were apparent. Firstly, prevalence, comorbidity and gender: In Eastern Mediterranean countries, many studies identify that the prevalence of dementia is high. As is the case elsewhere, many older adults in Eastern Mediterranean countries have at least one coexisting long-term condition, and some experience low life-satisfaction. Secondly, culture: In Eastern Mediterranean countries, the older adult is highly respected, and placement outside of the family home is considered an abandonment of family duty. The term dementia carries stigma, and it is widely believed that dementia is caused by ‘fate’. Thirdly, recognition and tools: There is a lack of verified assessment instruments to assess for dementia. Despite concerns about the cultural appropriateness of the Mini-Mental State Exam, particularly for people who have low literacy levels, and low literacy being the norm in Eastern Mediterranean countries, the Mini-Mental State Examination is the main assessment instrument. Translation and transition of non-Arabic assessment instruments and tools with psychometric properties presents a challenge for clinicians. Finally, workforce issues: health care workers lack knowledge about dementia, as dementia care is a relatively recent addition to the nursing and medical syllabi. While there were some inconsistencies in the papers published, many of the articles call for increasing educational programmes and health and social care policies to promote improved and practical gerontological nursing and medicine. Health care professionals need education about sociocultural, religious, and language needs to deliver improved culturally sensitive care.

The Association Between Physical Activity With Cognitive Function and Brain-Derived Neurotrophic Factor in People With Parkinson’s Disease: A Pilot Study

The objective of this study was to examine the effect of physical capacity on the relationship of brain-derived neurotrophic factor (BDNF) with cognitive function in people with PD. For this study, serum BDNF levels were measured in 29 PD participants and 30 healthy controls. Cognitive function was assessed using the Montreal Cognitive Assessment (MOCA) scale. Physical capacity was evaluated using the 6-min walk distance (6-MWD). Participants were categorized into low or high physical capacity group according to their 50th percentile 6-MWD. It was found that MOCA total score correlated with serum BDNF level (r = .44, P = .012) in the entire PD sample. This correlation remained significant only in the low physical capacity group (r = .62; P = .03) but not in the high physical capacity group (r = .31; P = .22). It was concluded that the relationship of BDNF with cognitive function might be dependent on physical capacity. The results are preliminary, thus future studies are needed to confirm these findings.

Variable PARK2 Mutations Cause Early-Onset Parkinson's Disease in a Small Restricted Population

Early-onset Parkinson's disease (EOPD) is less common than the typical adult-onset PD and may be associated with a genetic etiology. Mutations in several genes are known to cause autosomal recessive (AR) PD. This study aimed to detect the etiology of EOPD in consanguineous families or families living in a specific small geographic region in Israel. Six families with EOPD affecting more than a single individual were recruited. Homozygous mapping analysis using a single-nucleotide polymorphism-based array was performed in all families, followed by Sanger sequencing of related genes based on the mapping results. In addition, all families underwent PARK2 sequencing and testing for large deletions and duplications in PD-associated genes. Different truncating mutations were detected in the PARK2 gene among affected individuals of three families: c.996C>A (p.Cys332X) and c.101delA in either homozygous or compound heterozygous fashion. Exon 4 deletion was detected in a heterozygous manner in a late-onset PD and in homozygous state in early-onset disease in the same family. No disease-causing mutations were detected in any other tested genes. In total, mutations in the PARK2 gene were detected in four of the six tested families with a history of EOPD. These results further demonstrate the role of PARK2 in AR PD. We recommend genetic analysis for the PARK2 gene when AR PD is suspected.

Parkinson disease male-to-female ratios increase with age: French nationwide study and meta-analysis

BACKGROUND

Parkinson's disease (PD) is 1.5 times more frequent in men than women. Whether age modifies this ratio is unclear. We examined whether male-to-female (M-F) ratios change with age through a French nationwide prevalence/incidence study (2010) and a meta-analysis of incidence studies.

METHODS

We used French national drug claims databases to identify PD cases using a validated algorithm. We computed M-F prevalence/incidence ratios overall and by age using Poisson regression. Ratios were regressed on age to estimate their annual change. We identified all PD incidence studies with age/sex-specific data, and performed a meta-analysis of M-F ratios.

RESULTS

On the basis of 149 672 prevalent (50% women) and 25 438 incident (49% women) cases, age-standardised rates were higher in men (prevalence=2.865/1000; incidence=0.490/1000 person-years) than women (prevalence=1.934/1000; incidence=0.328/1000 person-years). The overall M-F ratio was 1.48 for prevalence and 1.49 for incidence. Prevalence and incidence M-F ratios increased by 0.05 and 0.14, respectively, per 10 years of age. Incidence was similar in men and women under 50 years (M-F ratio <1.2, p>0.20), and over 1.6 (p<0.001) times higher in men than women above 80 years (p trend <0.001). A meta-analysis of 22 incidence studies (14 126 cases, 46% women) confirmed that M- F ratios increased with age (0.26 per 10 years, p trend=0.005).

CONCLUSIONS

Age-increasing M-F ratios suggest that PD aetiology changes with age. Sex-related risk/protective factors may play a different role across the continuum of age at onset. This finding may inform aetiological PD research.

Construction of standardized Arabic questionnaires for screening neurological disorders (dementia, stroke, epilepsy, movement disorders, muscle and neuromuscular junction disorders)

A screening questionnaire is an important tool for early diagnosis of neurological disorders, and for epidemiological research. This screening instrument must be both feasible and valid. It must be accepted by the community and must be sensitive enough. So, the aim of this study was to prepare different Arabic screening questionnaires for screening different neurological disorders. This study was carried out in three stages. During the first stage, construction of separate questionnaires designed for screening the five major neurological disorders: cerebrovascular stroke, dementias, epilepsy, movement disorders, and muscle and neuromuscular disorders were done. Validation of the screening questionnaires was carried out in the second stage. Finally, questionnaire preparation was done in the third stage. Questions with the accepted sensitivity and specificity in each questionnaire formed the refined separate questionnaires.

Parkinson's disease

Parkinson's disease is a neurological disorder with evolving layers of complexity. It has long been characterised by the classical motor features of parkinsonism associated with Lewy bodies and loss of dopaminergic neurons in the substantia nigra. However, the symptomatology of Parkinson's disease is now recognised as heterogeneous, with clinically significant non-motor features. Similarly, its pathology involves extensive regions of the nervous system, various neurotransmitters, and protein aggregates other than just Lewy bodies. The cause of Parkinson's disease remains unknown, but risk of developing Parkinson's disease is no longer viewed as primarily due to environmental factors. Instead, Parkinson's disease seems to result from a complicated interplay of genetic and environmental factors affecting numerous fundamental cellular processes. The complexity of Parkinson's disease is accompanied by clinical challenges, including an inability to make a definitive diagnosis at the earliest stages of the disease and difficulties in the management of symptoms at later stages. Furthermore, there are no treatments that slow the neurodegenerative process. In this Seminar, we review these complexities and challenges of Parkinson's disease.

The VPS35 gene and Parkinson's disease

Parkinson's disease (PD), the second most common age-related neurodegenerative disease, is characterized by loss of dopaminergic and nondopaminergic neurons, leading to a variety of motor and nonmotor symptoms. In addition to environmental factors, genetic predisposition and specific gene mutations have been shown to play an important role in the pathogenesis of this disorder. Recently, the identification of the vacuolar protein sorting 35 homolog gene (VPS35), linked to autosomal dominant late-onset PD, has provided new clues to the pathogenesis of PD. Here we discuss the VPS35 gene, its protein function, and various pathways involved in Wnt/β-catenin signaling and in the role of DMT1 mediating the uptake of iron and iron translocation from endosomes to the cytoplasm. Further understanding of these mechanisms will undoubtedly provide new insights into the pathogenic mechanisms of PD and may lead to prevention and better treatment of the disorder.

Lrrk2 phosphorylates alpha synuclein at serine 129: Parkinson disease implications

Mutations in the alpha synuclein gene (SNCA) are the most potent cause of autosomal dominant Parkinson disease (PD) while mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common cause. We hypothesized that a direct interaction may exist between their protein products. Here we show that full-length Lrrk2 or fragments containing its kinase domain have a significant capacity to phosphorylate recombinant alpha synuclein (Asyn) at serine 129. Such phosphorylated Asyn is the major component of pathological deposits in PD. We further show that the G2019S mutation in Lrrk2, which is the most common genetic determinant of PD, has a significantly greater capacity than wild-type Lrrk2 to phosphorylate Asyn. This suggests that the G2019S mutant protein may cause PD by generating pathological levels of phosphorylated Asyn. Controlling Lrrk2 Asyn phosphokinase activity may be an approach to disease modifying therapy for PD and other synucleinopathies.

The neurology map of the Arab world

The Arab world covers a large geographical area over two continents, Africa and Asia and includes 23 countries ranging from low-to-high income. The estimated total population of the Arab world was around 318 million in 2005 and is projected to increase to 480 million in 2030. The percentage of people above the age of 60 will change from an average of 5.1% of the population in 2005 to 10.5% in 2030 with an increase in life expectancy from 68.2 years to 73.4 years. This will have a major effect on the burden of neurological diseases in the region. This article aims to review the available literature on the neurological supply and demand in the Arab countries and draws attention to the gaps in knowledge on the subject.

LRRK2 and neurodegeneration

Mutations in leucine-rich repeat kinase 2 gene (PARK8/LRRK2) encoding the protein Lrrk2 are causative of inherited and sporadic Parkinson's disease (PD) with phenotypic manifestations of frontotemporal lobar degeneration, corticobasal degeneration and associated motor neuron disease in some patients, and with variable penetrance. Neuropathology is characterized by loss of dopaminergic neurons in the substantia nigra pars compacta in all cases with accompanying Lewy pathology, or tau pathology or without intraneuronal inclusions, thus indicating that mutations in LRRK2 are not always manifested as Lewy body disease (LBD) or as alpha-synucleinopathy. Molecular studies have not disclosed clear association between nerve cell degeneration and modifications in the kinase activity of Lrrk2, and the pathogenesis of LRRK2 mutations remains unknown. Several morphological studies have suggested that Lrrk2 is a component of Lewy bodies and aberrant neurites in sporadic PD and Dementia with Lewy bodies, whereas other studies have indicated that Lrrk2 does not participate in Lewy body composition. Likewise, some studies have shown Lrrk2 immunoreactivity in hyper-phosphorylated tau inclusions in Alzheimer's disease (AD) and other tauopathies, whereas other studies did not find Lrrk2 in hyper-phosphorylated tau inclusions. We have used three currently used anti-Lrrk2 antibodies (NB-300-268, NB-300-267 and AP7099b) and concluded that these differences are largely dependent on the antibodies used and, particularly, on the interpretation of the origin of the multiple bands of low molecular weight species, in addition to the band corresponding to full-length Lrrk2, that recognize the majority of these antibodies. A review of the available data and our results indicate that full-length Lrrk2 is not a major component of Lewy bodies in LBDs, and of hyper-phosphorylated tau inclusions in AD and tauopathies. Bands of low molecular weight are probably not the result of post-mortem artefacts as they are also present in cultured cells processed under optimal conditions. Truncated forms of Lrrk2 and additional transcripts related with LRRK2, in the absence of spliced forms of Lrrk2 may account for Lrrk2 immunoreactivity in distinct intraneuronal inclusions.

A new complex homozygous large rearrangement of the PINK1 gene in a Sudanese family with early onset Parkinson's disease

PARK2 and PINK1 gene mutations are involved in recessive early onset Parkinson's disease (EOPD). In order to determine the causative mutations in three affected sibs from a consanguineous Sudanese family with EOPD, multiplex ligation-dependent probe amplification was performed and revealed that the patients were homozygous for a deletion of PINK1 exons 4 to 8. Breakpoint analysis revealed a complex rearrangement combining a large deletion and the insertion of a sequence duplicated from the DDOST gene intron 2, located near the PINK1 gene. As breakpoint sequences displayed only three base pairs of homology, this rearrangement may result from Fork Stalling and Template Switching mechanism. This third large rearrangement of PINK1 enlarges the mutation spectrum and, together with recent published data in Tunisian patients with EOPD, points out that PINK1 gene analysis, including search for large rearrangement, should be considered in early onset recessive PD patients, particularly those from Arab origin.

MDPD: an integrated genetic information resource for Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting millions of people. Both environmental and genetic factors play important roles in its causation and development. Genetic analysis has shown that over 100 genes are correlated with the etiology and pathology of PD. However, accessing genetic information in a consistent and fruitful way is not an easy task. The Mutation Database for Parkinson's Disease (MDPD) is designed to fulfill the need for information integration so that users can easily retrieve, inspect and enhance their knowledge on PD. The database contains 2391 entries on 202 genes extracted from 576 publications and manually examined by biomedical researchers. Each genetic substitution and the resulting impact are clearly labelled and linked to its primary reference. Every reported gene has a summary page that provides information on the variation impact, mutation type, the studied population, mutation position and reference collection. In addition, MDPD provides a unique functionality for users to compare the differences on the type of mutations among ethnic groups. As such, we hope that MDPD will serve as a valuable tool to bridge the gap between genetic analysis and clinical practice. MDPD is publicly accessible at http://datam.i2r.a-star.edu.sg/mdpd/.