1 The John Walton Muscular Dystrophy Research Center, Newcastle University and Newcastle Hospitals NHS Foundation Trust, The International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK.
2 The John Walton Muscular Dystrophy Research Center, Newcastle University and Newcastle Hospitals NHS Foundation Trust, The International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK; Neuromuscular Disorders Unit, Neurology Department, Hospital de la Santa Creu I Sant Pau, de Barcelona, Spain.
3 The John Walton Muscular Dystrophy Research Center, Newcastle University and Newcastle Hospitals NHS Foundation Trust, The International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK. Electronic address: volker.straub@ncl.ac.uk.