[1] Newcastle Univ, Inst Genet Med, John Walton Muscular Dystrophy Res Ctr, Cent Pkwy, Newcastle Upon Tyne, Tyne & Wear, England
[2] Newcastle Hosp NHS Fdn Trust, Cent Pkwy, Newcastle Upon Tyne, Tyne & Wear, England
[3] Tampere Univ, Neuromuscular Res Ctr, Dept Neurol, Tampere, Finland
[4] Univ Hosp, Tampere, Finland
[5] Univ Helsinki, Folkhalsan Inst Genet, Dept Med Genet, Helsinki, Finland
[6] Vaasa Cent Hosp, Dept Neurol, Vaasa, Finland