DISC1 and major depressive disorder: For example, two overlapping and opposite strand genes on chromosome 1, DISC1 and DISC2, are specifically disrupted by a t(1;11; q42.1; q14.3) balanced translocation, in a large Scottish pedigree, resulting in a cohort with several major mental illnesses such as schizophrenia, bipolar affective disorder, and recurrent major depression (St Clair et al., 1990; Millar et al., 2000, 2001; Blackwood et al., 2001; Muir et al., 2008).