[1] Univ Munich, Friedrich Baur Inst, Dept Neurol, D-80336 Munich, Germany
[2] Univ Belgrade, Fac Med, Clin Pediat & Adolescent Neurol & Psychiat, Belgrade 11000, Serbia
[3] Ruhr Univ Bochum, Inst Humangenet, D-44801 Bochum, Germany
[4] Newcastle Univ, Inst Human Genet, Int Ctr Life, Newcastle Upon Tyne NE1 3BZ, Tyne & Wear, England