^aDepartment of Pathology, University of Sydney, Australia

^bDepartment of Neurology, Concord Hospital, Sydney, Australia

^cElectron Microscopy Unit, Central Sydney Area Health Service, Sydney, Australia

^dInstitute for Neuromuscular Research, The Children’s Hospital at Westmead, Australia

^eCentre for Neuromuscular and Neurological Disorders, University of Western Australia, Australian Neuromuscular Research Institute and Centre for Medical Research, Australian Institute for Medical Research, QEII Medical Centre, Nedlands, WA, Australia

^fDiscipline of Paediatrics and Child Health, Faculty of Medicine, University of Sydney, Australia