1 Neuromuscular Diseases Unit, European Reference Network on Rare Neuromuscular Diseases (ERN EURO-NMD), Department of Neurology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.
2 Department of Clinical Neurophysiology, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.
3 Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.