[1] Tampere Univ, Neuromuscular Res Ctr, Dept Neurol, Tampere, Finland
[2] Univ Hosp, Tampere, Finland
[3] Oulu Univ Hosp, Dept Neurol, Oulu, Finland
[4] Univ Oulu, Oulu, Finland
[5] Lapland Cent Hosp, Dept Neurol, Rovaniemi, Finland
[6] Oulu Univ Hosp, Dept Clin Genet, Oulu, Finland
[7] Oulu Univ Hosp, Med Res Ctr Oulu, Oulu, Finland
[8] Univ Helsinki, Folkhalsan Inst Genet, Helsinki, Finland
[9] Univ Helsinki, Haartman Inst, Dept Med Genet, Helsinki, Finland
[10] Vaasa Cent Hosp, Dept Neurol, Vaasa, Finland