[1] Univ Hosp Liege, Div Child Neurol, Reference Ctr Neuromuscular Dis, Dept Pediat, Blvd 12eme Ligne, B-4000 Liege, Belgium
[2] Univ Liege, CRMN Liege, CHR Citadelle, Blvd 12eme Ligne, B-4000 Liege, Belgium
[3] Univ Med Ctr Ljubljana, Univ Childrens Hosp, Dept Pediat Neurol, Bohoriceva 20, Ljubljana 1525, Slovenia
[4] Univ Oxford, Dept Paediat, MDUK Neuromuscular Ctr, Oxford, England
[5] Univ Ljubljana, Med Fac, Ljubljana, Slovenia