[1] Univ Aberdeen, Sch Med, Dept Mental Hlth, Aberdeen AB25 2ZD, Scotland
[2] Univ Aberdeen, Sch Med, Dept Mol & Cellular Biol, Aberdeen AB25 2ZD, Scotland
[3] Addenbrookes Hosp, Dept Med Genet, Cambridge CB2 2QQ, England
[4] So Gen Hosp, Inst Neurosci, Dept Neurol, Glasgow G51 4TF, Lanark, Scotland