Browsing by Author "Bonifati, Vincenzo"

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    Genetic Testing in Parkinson's Disease
    (Wiley, 2023) Pal, Gian; Cook, Lola; Schulze, Jeanine; Verbrugge, Jennifer; Alcalay, Roy N.; Merello, Marcelo; Sue, Carolyn M.; Bardien, Soraya; Bonifati, Vincenzo; Chung, Sun Ju; Foroud, Tatiana; Gatto, Emilia; Hall, Anne; Hattori, Nobutaka; Lynch, Tim; Marder, Karen; Mascalzoni, Deborah; Novaković, Ivana; Thaler, Avner; Raymond, Deborah; Salari, Mehri; Shalash, Ali; Suchowersky, Oksana; Mencacci, Niccolò E.; Simuni, Tanya; Saunders-Pullman, Rachel; Klein, Christine; Medical and Molecular Genetics, School of Medicine
    Genetic testing for persons with Parkinson's disease is becoming increasingly common. Significant gains have been made regarding genetic testing methods, and testing is becoming more readily available in clinical, research, and direct-to-consumer settings. Although the potential utility of clinical testing is expanding, there are currently no proven gene-targeted therapies, but clinical trials are underway. Furthermore, genetic testing practices vary widely, as do knowledge and attitudes of relevant stakeholders. The specter of testing mandates financial, ethical, and physician engagement, and there is a need for guidelines to help navigate the myriad of challenges. However, to develop guidelines, gaps and controversies need to be clearly identified and analyzed. To this end, we first reviewed recent literature and subsequently identified gaps and controversies, some of which were partially addressed in the literature, but many of which are not well delineated or researched. Key gaps and controversies include: (1) Is genetic testing appropriate in symptomatic and asymptomatic individuals without medical actionability? (2) How, if at all, should testing vary based on ethnicity? (3) What are the long-term outcomes of consumer- and research-based genetic testing in presymptomatic PD? (4) What resources are needed for clinical genetic testing, and how is this impacted by models of care and cost-benefit considerations? Addressing these issues will help facilitate the development of consensus and guidelines regarding the approach and access to genetic testing and counseling. This is also needed to guide a multidisciplinary approach that accounts for cultural, geographic, and socioeconomic factors in developing testing guidelines.
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    International Genetic Testing and Counseling Practices for Parkinson's Disease
    (Wiley, 2023) Saunders-Pullman, Rachel; Raymond, Deborah; Ortega, Roberto A.; Shalash, Ali; Gatto, Emilia; Salari, Mehri; Markgraf, Maggie; Alcalay, Roy N.; Mascalzoni, Deborah; Mencacci, Niccolò E.; Bonifati, Vincenzo; Merello, Marcelo; Chung, Sun Ju; Novakovic, Ivana; Bardien, Soraya; Pal, Gian; Hall, Anne; Hattori, Nobutaka; Lynch, Timothy; Thaler, Avner; Sue, Carolyn M.; Foroud, Tatiana; Verbrugge, Jennifer; Schulze, Jeanine; Cook, Lola; Marder, Karen; Suchowersky, Oksana; Klein, Christine; Simuni, Tatyana; Medical and Molecular Genetics, School of Medicine
    Background: There is growing clinical and research utilization of genetic testing in Parkinson's disease (PD), including direct-to-consumer testing. Objectives: The aim is to determine the international landscape of genetic testing in PD to inform future worldwide recommendations. Methods: A web-based survey assessing current practices, concerns, and barriers to genetic testing and counseling was administered to the International Parkinson and Movement Disorders Society membership. Results: Common hurdles across sites included cost and access to genetic testing, and counseling, as well as education on genetic counseling. Region-dependent differences in access to and availability of testing and counseling were most notable in Africa. High-income countries also demonstrated heterogeneity, with European nations more likely to have genetic testing covered through insurance than Pan-American and Asian countries. Conclusions: This survey highlights not only diversity of barriers in different regions but also the shared and highly actionable needs for improved education and access to genetic counseling and testing for PD worldwide. © 2023 International Parkinson and Movement Disorder Society.
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    A new alpha-synuclein missense variant (Thr72Met) in two Turkish families with Parkinson's disease
    (Elsevier, 2021-08) Fevga, Christina; Park, Yangshin; Lohmann, Ebba; Kievit, Anneke J.; Breedveld, Guido J.; Ferraro, Federico; de Boer, Leon; van Minkelen, Rick; Hanagasi, Hasmet; Boon, Agnita; Wang, Wei; Petsko, Gregory A.; Hoang, Quyen Q.; Emre, Murat; Bonifati, Vincenzo; Biochemistry and Molecular Biology, School of Medicine
    Introduction: Missense variants and multiplications of the alpha-synuclein gene (SNCA) are established as rare causes of autosomal dominant forms of Parkinson's Disease (PD). Methods: Two families of Turkish origins with PD were studied; the SNCA coding region was analyzed by Sanger sequencing, and by whole exome sequencing (WES) in the index patient of the first and the second family, respectively. Co-segregation studies and haplotype analysis across the SNCA locus were carried out. Functional studies included in vitro thioflavin-T aggregation assay and in silico structural modelling of the alpha-synuclein (α-syn) protein. Results: We identified a novel heterozygous SNCA variant, c.215C > T (p.Thr72Met), segregating with PD in a total of four members in the two families. A shared haplotype across the SNCA locus was found among variant carriers, suggestive of a common ancestor. We next showed that the Thr72Met α-syn displays enhanced aggregation in-vitro, compared to the wild-type species. In silico analysis of a tetrameric α-syn structural model revealed that Threonine 72 lies in the tetrameric interface, and substitution with the much larger methionine residue could potentially destabilize the tetramer. Conclusion: We present clinical, genetic, and functional data supporting a causative role of the SNCA c.215C > T (p.Thr72Met) variant in familial PD. Testing for this variant in patients with PD, especially of Turkish origin, might detect additional carriers. Further functional analyses might offer new insights into the shared biochemical properties of the PD-causing SNCA missense variants, and how they lead to neurodegeneration.