Biallelic MADD variants cause a phenotypic spectrum ranging from developmental delay to a multisystem disorder

Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany

Klinik für Neuropädiatrie und angeborene Stoffwechselerkrankungen, Klinikum Oldenburg, Oldenburg, Germany

Bioinformatics Core Unit, University Medical Center Hamburg-Eppendorf, Hamburg, Germany

Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany

Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Canada

Human Genetics Department, McGill University, Montreal, Canada

GeneDx, Gaithersburg, USA

Division of Genetics, Department of Pediatrics, King Abdullah specialized Children’s Hospital, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia

Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia

King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia

Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, USA

Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, USA

Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, USA

Department for Neuropediatrics, University Children’s Hospital, Ruhr University Bochum, Bochum, Germany

Department of Pediatrics, Prignitz Hospital, Brandenburg Medical School, Germany

Institute of Human Genetics, University Medical Center Leipzig, Leipzig, Germany

Universitätsklinikum Leipzig - AöR, University of Leipzig, Hospital for Children and Adolescents, Leipzig, Germany

CeGaT GmbH and Praxis für Humangenetik Tübingen, Tübingen, Germany

Dr. von Hauner Children’s Hospital, University of Munich, Munich, Germany

Medicover Humangenetik Hannover, Hanover, Germany

Medical Genetic Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy

Child and Adolescent Neuropsychiatric Unit, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy

Laboratorio di Genetica Medica, ASST Papa Giovanni XXIII, Bergamo, Italy

Center for Human Genetics, KU Leuven, Leuven, Belgium

Centre for Developmental Disabilities, Department of Development and Regeneration, KU Leuven, Leuven, Belgium

Center for Metabolic Diseases, KU Leuven, Leuven, Belgium

Unidad de Patología Compleja, Servicio de Pediatría, Hospital Universitario La Paz, Madrid, Spain

Instituto de Genética Médica y Molecular (INGEMM), Hospital Universitario La Paz, IdiPAZ, CIBERER, ISCIII, Madrid, Spain

Center of Medical Genetics, University Hospital Antwerp, Antwerp, Belgium

Department of Pediatric Neurology, University Hospital Antwerp, Antwerp, Belgium

Department of Medical Genetics, University of Antwerp, Antwerp, Belgium

Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK

Next Generation Genetic Polyclinic, Mashhad, Iran

Genetics Research Centre, Molecular and Clinical Sciences Institute, St. George’s, University, London, UK

Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

Genetic Center of Khorasan Razavi, Mashhad, Iran

Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic

Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic

Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA

Division of Genetics and Metabolism, College of Medicine, University of South Florida, Tampa, Florida, USA

Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany

Institute of Human Genetics, Jena University Hospital, Jena, Germany