[1] Univ Edinburgh, Royal Edinburgh Hosp, Dept Psychiat, Edinburgh EH10 5HF, Midlothian, Scotland
[2] Univ Edinburgh, Western Gen Hosp, Mol Med Ctr, Edinburgh, Midlothian, Scotland
[3] Univ Cambridge, Dept Clin Vet Med, Cambridge CB3 0ES, England
[4] Univ Alberta, Dept Genet, Edmonton, AB T6G 2E9, Canada