Browsing by Author "Beetz, Christian"

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    Functional and clinical studies reveal pathophysiological complexity of CLCN4-related neurodevelopmental condition
    (Springer Nature, 2023) Palmer, Elizabeth E.; Pusch, Michael; Picollo, Alessandra; Forwood, Caitlin; Nguyen, Matthew H.; Suckow, Vanessa; Gibbons, Jessica; Hoff, Alva; Sigfrid, Lisa; Megarbane, Andre; Nizon, Mathilde; Cogné, Benjamin; Beneteau, Claire; Alkuraya, Fowzan S.; Chedrawi, Aziza; Hashem, Mais O.; Stamberger, Hannah; Weckhuysen, Sarah; Vanlander, Arnaud; Ceulemans, Berten; Rajagopalan, Sulekha; Nunn, Kenneth; Arpin, Stéphanie; Raynaud, Martine; Motter, Constance S.; Ward-Melver, Catherine; Janssens, Katrien; Meuwissen, Marije; Beysen, Diane; Dikow, Nicola; Grimmel, Mona; Haack, Tobias B.; Clement, Emma; McTague, Amy; Hunt, David; Townshend, Sharron; Ward, Michelle; Richards, Linda J.; Simons, Cas; Costain, Gregory; Dupuis, Lucie; Mendoza-Londono, Roberto; Dudding-Byth, Tracy; Boyle, Jackie; Saunders, Carol; Fleming, Emily; El Chehadeh, Salima; Spitz, Marie-Aude; Piton, Amelie; Gerard, Bénédicte; Warde, Marie-Thérèse Abi; Rea, Gillian; McKenna, Caoimhe; Douzgou, Sofia; Banka, Siddharth; Akman, Cigdem; Bain, Jennifer M.; Sands, Tristan T.; Wilson, Golder N.; Silvertooth, Erin J.; Miller, Lauren; Lederer, Damien; Sachdev, Rani; Macintosh, Rebecca; Monestier, Olivier; Karadurmus, Deniz; Collins, Felicity; Carter, Melissa; Rohena, Luis; Willemsen, Marjolein H.; Ockeloen, Charlotte W.; Pfundt, Rolph; Kroft, Sanne D.; Field, Michael; Laranjeira, Francisco E. R.; Fortuna, Ana M.; Soares, Ana R.; Michaud, Vincent; Naudion, Sophie; Golla, Sailaja; Weaver, David D.; Bird, Lynne M.; Friedman, Jennifer; Clowes, Virginia; Joss, Shelagh; Pölsler, Laura; Campeau, Philippe M.; Blazo, Maria; Bijlsma, Emilia K.; Rosenfeld, Jill A.; Beetz, Christian; Powis, Zöe; McWalter, Kirsty; Brandt, Tracy; Torti, Erin; Mathot, Mikaël; Mohammad, Shekeeb S.; Armstrong, Ruth; Kalscheuer, Vera M.; Medical and Molecular Genetics, School of Medicine
    Missense and truncating variants in the X-chromosome-linked CLCN4 gene, resulting in reduced or complete loss-of-function (LOF) of the encoded chloride/proton exchanger ClC-4, were recently demonstrated to cause a neurocognitive phenotype in both males and females. Through international clinical matchmaking and interrogation of public variant databases we assembled a database of 90 rare CLCN4 missense variants in 90 families: 41 unique and 18 recurrent variants in 49 families. For 43 families, including 22 males and 33 females, we collated detailed clinical and segregation data. To confirm causality of variants and to obtain insight into disease mechanisms, we investigated the effect on electrophysiological properties of 59 of the variants in Xenopus oocytes using extended voltage and pH ranges. Detailed analyses revealed new pathophysiological mechanisms: 25% (15/59) of variants demonstrated LOF, characterized by a "shift" of the voltage-dependent activation to more positive voltages, and nine variants resulted in a toxic gain-of-function, associated with a disrupted gate allowing inward transport at negative voltages. Functional results were not always in line with in silico pathogenicity scores, highlighting the complexity of pathogenicity assessment for accurate genetic counselling. The complex neurocognitive and psychiatric manifestations of this condition, and hitherto under-recognized impacts on growth, gastrointestinal function, and motor control are discussed. Including published cases, we summarize features in 122 individuals from 67 families with CLCN4-related neurodevelopmental condition and suggest future research directions with the aim of improving the integrated care for individuals with this diagnosis.
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    Relevance of genetic testing in the gene-targeted trial era: the Rostock Parkinson's disease study
    (Oxford University Press, 2024) Westenberger, Ana; Skrahina, Volha; Usnich, Tatiana; Beetz, Christian; Vollstedt, Eva-Juliane; Laabs, Björn-Hergen; Paul, Jefri J.; Curado, Filipa; Skobalj, Snezana; Gaber, Hanaa; Olmedillas, Maria; Bogdanovic, Xenia; Ameziane, Najim; Schell, Nathalie; Aasly, Jan Olav; Afshari, Mitra; Agarwal, Pinky; Aldred, Jason; Alonso-Frech, Fernando; Anderson, Roderick; Araújo, Rui; Arkadir, David; Avenali, Micol; Balal, Mehmet; Benizri, Sandra; Bette, Sagari; Bhatia, Perminder; Bonello, Michael; Braga-Neto, Pedro; Brauneis, Sarah; Costa Cardoso, Francisco Eduardo; Cavallieri, Francesco; Classen, Joseph; Cohen, Lisa; Coletta, Della; Crosiers, David; Cullufi, Paskal; Dashtipour, Khashayar; Demirkiran, Meltem; de Carvalho Aguiar, Patricia; De Rosa, Anna; Djaldetti, Ruth; Dogu, Okan; Dos Santos Ghilardi, Maria Gabriela; Eggers, Carsten; Elibol, Bulent; Ellenbogen, Aaron; Ertan, Sibel; Fabiani, Giorgio; Falkenburger, Björn H.; Farrow, Simon; Fay-Karmon, Tsviya; Ferencz, Gerald J.; Fonoff, Erich Talamoni; Fragoso, Yara Dadalti; Genç, Gençer; Gorospe, Arantza; Grandas, Francisco; Gruber, Doreen; Gudesblatt, Mark; Gurevich, Tanya; Hagenah, Johann; Hanagasi, Hasmet A.; Hassin-Baer, Sharon; Hauser, Robert A.; Hernández-Vara, Jorge; Herting, Birgit; Hinson, Vanessa K.; Hogg, Elliot; Hu, Michele T.; Hummelgen, Eduardo; Hussey, Kelly; Infante, Jon; Isaacson, Stuart H.; Jauma, Serge; Koleva-Alazeh, Natalia; Kuhlenbäumer, Gregor; Kühn, Andrea; Litvan, Irene; López-Manzanares, Lydia; Luxmore, McKenzie; Manandhar, Sujeena; Marcaud, Veronique; Markopoulou, Katerina; Marras, Connie; McKenzie, Mark; Matarazzo, Michele; Merello, Marcelo; Mollenhauer, Brit; Morgan, John C.; Mullin, Stephen; Musacchio, Thomas; Myers, Bennett; Negrotti, Anna; Nieves, Anette; Nitsan, Zeev; Oskooilar, Nader; Öztop-Çakmak, Özgür; Pal, Gian; Pavese, Nicola; Percesepe, Antonio; Piccoli, Tommaso; Pinto de Souza, Carolina; Prell, Tino; Pulera, Mark; Raw, Jason; Reetz, Kathrin; Reiner, Johnathan; Rosenberg, David; Ruiz-Lopez, Marta; Ruiz Martinez, Javier; Sammler, Esther; Santos-Lobato, Bruno Lopes; Saunders-Pullman, Rachel; Schlesinger, Ilana; Schofield, Christine M.; Schumacher-Schuh, Artur F.; Scott, Burton; Sesar, Ángel; Shafer, Stuart J.; Sheridan, Ray; Silverdale, Monty; Sophia, Rani; Spitz, Mariana; Stathis, Pantelis; Stocchi, Fabrizio; Tagliati, Michele; Tai, Yen F.; Terwecoren, Annelies; Thonke, Sven; Tönges, Lars; Toschi, Giulia; Tumas, Vitor; Urban, Peter Paul; Vacca, Laura; Vandenberghe, Wim; Valente, Enza Maria; Valzania, Franco; Vela-Desojo, Lydia; Weill, Caroline; Weise, David; Wojcieszek, Joanne; Wolz, Martin; Yahalom, Gilad; Yalcin-Cakmakli, Gul; Zittel, Simone; Zlotnik, Yair; Kandaswamy, Krishna K.; Balck, Alexander; Hanssen, Henrike; Borsche, Max; Lange, Lara M.; Csoti, Ilona; Lohmann, Katja; Kasten, Meike; Brüggemann, Norbert; Rolfs, Arndt; Klein, Christine; Bauer, Peter; Neurology, School of Medicine
    Estimates of the spectrum and frequency of pathogenic variants in Parkinson's disease (PD) in different populations are currently limited and biased. Furthermore, although therapeutic modification of several genetic targets has reached the clinical trial stage, a major obstacle in conducting these trials is that PD patients are largely unaware of their genetic status and, therefore, cannot be recruited. Expanding the number of investigated PD-related genes and including genes related to disorders with overlapping clinical features in large, well-phenotyped PD patient groups is a prerequisite for capturing the full variant spectrum underlying PD and for stratifying and prioritizing patients for gene-targeted clinical trials. The Rostock Parkinson's disease (ROPAD) study is an observational clinical study aiming to determine the frequency and spectrum of genetic variants contributing to PD in a large international cohort. We investigated variants in 50 genes with either an established relevance for PD or possible phenotypic overlap in a group of 12 580 PD patients from 16 countries [62.3% male; 92.0% White; 27.0% positive family history (FH+), median age at onset (AAO) 59 years] using a next-generation sequencing panel. Altogether, in 1864 (14.8%) ROPAD participants (58.1% male; 91.0% White, 35.5% FH+, median AAO 55 years), a PD-relevant genetic test (PDGT) was positive based on GBA1 risk variants (10.4%) or pathogenic/likely pathogenic variants in LRRK2 (2.9%), PRKN (0.9%), SNCA (0.2%) or PINK1 (0.1%) or a combination of two genetic findings in two genes (∼0.2%). Of note, the adjusted positive PDGT fraction, i.e. the fraction of positive PDGTs per country weighted by the fraction of the population of the world that they represent, was 14.5%. Positive PDGTs were identified in 19.9% of patients with an AAO ≤ 50 years, in 19.5% of patients with FH+ and in 26.9% with an AAO ≤ 50 years and FH+. In comparison to the idiopathic PD group (6846 patients with benign variants), the positive PDGT group had a significantly lower AAO (4 years, P = 9 × 10-34). The probability of a positive PDGT decreased by 3% with every additional AAO year (P = 1 × 10-35). Female patients were 22% more likely to have a positive PDGT (P = 3 × 10-4), and for individuals with FH+ this likelihood was 55% higher (P = 1 × 10-14). About 0.8% of the ROPAD participants had positive genetic testing findings in parkinsonism-, dystonia/dyskinesia- or dementia-related genes. In the emerging era of gene-targeted PD clinical trials, our finding that ∼15% of patients harbour potentially actionable genetic variants offers an important prospect to affected individuals and their families and underlines the need for genetic testing in PD patients. Thus, the insights from the ROPAD study allow for data-driven, differential genetic counselling across the spectrum of different AAOs and family histories and promote a possible policy change in the application of genetic testing as a routine part of patient evaluation and care in PD.