[1] Royal North Shore Hosp, Dept Clin Genet, St Leonards, NSW 2064, Australia
[2] Univ Sydney, Fac Hlth & Med, Sydney Med Sch, Sydney, NSW, Australia
[3] Concord Repatriat Gen Hosp, Dept Neurol, Concord, NSW, Australia
[4] Univ Sydney, Sydney Med Sch, Sydney, NSW, Australia
[5] Childrens Hosp, Kids Neurosci, Westmead, NSW, Australia
[6] Royal Melbourne Hosp, Dept Neurosurg, Parkville, Vic, Australia
[7] Royal Melbourne Hosp, Dept Surg, Parkville, Vic, Australia