April 2021; 7 (2) ArticleOpen Access
LBSL
Case Series and DARS2 Variant Analysis in Early Severe Forms With Unexpected Presentations
View ORCID ProfileMenno D. Stellingwerff, Sonia Figuccia, Emanuele Bellacchio, Karin Alvarez, View ORCID ProfileClaudia Castiglioni, Pinar Topaloglu, Chloe A. Stutterd, Corrie E. Erasmus, Amarilis Sanchez‐Valle, Sebastien Lebon, Sarah Hughes, Thomas Schmitt-Mechelke, Gessica Vasco, Gabriel Chow, View ORCID ProfileElisa Rahikkala, Cristina Dallabona, Cecilia Okuma, Chiara Aiello, Paola Goffrini, Truus E.M. Abbink, Enrico S. Bertini, Marjo S. Van der Knaap
First published February 2, 2021, DOI: https://doi.org/10.1212/NXG.0000000000000559
Menno D. Stellingwerff
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Sonia Figuccia
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Emanuele Bellacchio
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Karin Alvarez
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Claudia Castiglioni
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Pinar Topaloglu
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Chloe A. Stutterd
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Corrie E. Erasmus
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Amarilis Sanchez‐Valle
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Sebastien Lebon
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Sarah Hughes
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Thomas Schmitt-Mechelke
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Gessica Vasco
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Gabriel Chow
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Elisa Rahikkala
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Cristina Dallabona
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Cecilia Okuma
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Chiara Aiello
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Paola Goffrini
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Truus E.M. Abbink
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Enrico S. Bertini
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
Marjo S. Van der Knaap
From the Department of Child Neurology, Emma Childrens Hospital, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, The Netherlands (M.D.S., T.E.M.A.); Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy (S.F., C.D., P.G.); Area di Ricerca Genetica e Malattie Rare (E.B.), Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Laboratory of Oncology and Molecular Genetics (K.A.), Clínica las Condes, Santiago, Chile; Department of Pediatric Neurology (C.C.), Clínica Las Condes, Santiago, Chile; Division of Child Neurology (P.T.), Department of Neurology, Istanbul Faculty of Medicine, Turkey; Department of Paediatrics (C.A.S.), Royal Childrens Hospital, Murdoch Childrens Research Institute and University of Melbourne, Victoria, Australia; Pediatric Neurology (C.E.E.), Radboud University Medical Center, Amalia Childrens Hospital, Nijmegen, The Netherlands; Department of Pediatrics (A.S.-V.), University of South Florida, Tampa; Unit of Pediatric Neurology and Neurorehabilitation (S.L.), Department WomanMother-Child, Lausanne University Hospital, Switzerland; Community Pediatrics, Royal Berkshire Hospital, Reading (S.H.), United Kingdom; Neuropediatric Department (T.S.-M.), Childrens Hospital, Luzern, Switzerland; Unit of Neurorehabilitation (G.V.), Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; Paediatric Neurology (G.C.), Nottingham Childrens Hospital, United Kingdom; PEDEGO Research Unit (E.R.), Medical Research Center and Department of Clinical Genetics, University of Oulu and Oulu University Hospital, Finland; Radiology (C.O.), Clínica las Condes, Santiago, Chile; Unit of Neuromuscular and Neurodegenerative Disorders (E.S.B), Area di Ricerca Genetica e Malattie Rare and Department of Neurosciences, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy; and Department of Child Neurology (M.S.v.d.K.), Emma Childrens Hospital and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands.
LBSL
Case Series and DARS2 Variant Analysis in Early Severe Forms With Unexpected Presentations
Menno D. Stellingwerff, Sonia Figuccia, Emanuele Bellacchio, Karin Alvarez, Claudia Castiglioni, Pinar Topaloglu, Chloe A. Stutterd, Corrie E. Erasmus, Amarilis Sanchez‐Valle, Sebastien Lebon, Sarah Hughes, Thomas Schmitt-Mechelke, Gessica Vasco, Gabriel Chow, Elisa Rahikkala, Cristina Dallabona, Cecilia Okuma, Chiara Aiello, Paola Goffrini, Truus E.M. Abbink, Enrico S. Bertini, Marjo S. Van der Knaap
Neurol Genet Apr 2021, 7 (2) e559; DOI: 10.1212/NXG.0000000000000559
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Abstract
Objective Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) is regarded a relatively mild leukodystrophy, diagnosed by characteristic long tract abnormalities on MRI and biallelic variants in DARS2, encoding mitochondrial aspartyl-tRNA synthetase (mtAspRS). DARS2 variants in LBSL are almost invariably compound heterozygous; in 95% of cases, 1 is a leaky splice site variant in intron 2. A few severely affected patients, still fulfilling the MRI criteria, have been described. We noticed highly unusual MRI presentations in 15 cases diagnosed by WES. We examined these cases to determine whether they represent consistent novel LBSL phenotypes.
Methods We reviewed clinical features, MRI abnormalities, and gene variants and investigated the variants' impact on mtAspRS structure and mitochondrial function.
Results We found 2 MRI phenotypes: early severe cerebral hypoplasia/atrophy (9 patients, group 1) and white matter abnormalities without long tract involvement (6 patients, group 2). With antenatal onset, microcephaly, and arrested development, group 1 patients were most severely affected. DARS2 variants were severer than for classic LBSL and severer for group 1 than group 2. All missense variants hit mtAspRS regions involved in tRNAAsp binding, aspartyl-adenosine-5′-monophosphate binding, and/or homodimerization. Missense variants expressed in the yeast DARS2 ortholog showed severely affected mitochondrial function.
Conclusions DARS2 variants are associated with highly heterogeneous phenotypes. New MRI presentations are profound cerebral hypoplasia/atrophy and white matter abnormalities without long tract involvement. Our findings have implications for diagnosis and understanding disease mechanisms, pointing at dominant neuronal/axonal involvement in severe cases. In line with this conclusion, activation of biallelic DARS2 null alleles in conditional transgenic mice leads to massive neuronal apoptosis.
Glossary
- ADC=
- apparent diffusion coefficient;
- LBSL=
- Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation;
- mtAspRS=
- mitochondrial Aspartyl tRNA synthetase;
- PDB=
- Protein Data Bank;
- SC=
- synthetic complete;
- WES=
- whole-exome sequencing
Footnotes
Go to Neurology.org/NG for full disclosures. Funding information is provided at the end of the article.
The Article Processing Charge was funded by VU Medical Center.
- Received September 15, 2020.
- Accepted in final form December 3, 2020.
- Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.
This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND), which permits downloading and sharing the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.
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