On chromosome 1p13.3 (Figure 2), low P-values spanned two broad LD blocks that include many genes (Table 3), including those encoding two G proteins (GNAI3, GNAT2), a G-protein coupled receptor related to biogenic amine receptors (GPR61), a transcription factor gene resembling those involved in neurodegenerative syndromes (ATXN7L2), and genes involved in neuronal growth and plasticity (AMIGO1) and neuronal apoptosis (SORT1). Current hypotheses suggest that both G-protein coupled signaling and mechanisms of neuronal plasticity are relevant to the pathophysiology of MDD and the actions of antidepressant drugs.51
