The ankyrin 3 gene (ANK3) encodes the ankyrin G protein, a key scaffolding protein that anchors integral membrane proteins to the spectrin/actin cytoskeleton. Amongst other functions, ankyrin G has fundamental roles in neurotransmission by clustering sodium and potassium channels at the neuron axon initial segments and Nodes of Ranvier (Zhou et al., 1998) that initiate and propagate action potentials, as well as in formation and maintenance of neuron axodendritic structure, and regulating neuronal excitability (Leussis et al., 2012b). In recent years, ANK3 has attracted the interest of psychiatric geneticists after being associated with bipolar disorder in multiple genome-wide association studies (GWAS), GWAS meta-analyses, and targeted replication studies. To date, the SNPs most reliably associated with bipolar disorder are rs9804190 at the 3′ end of ANK3 (Schulze et al., 2009; Sklar et al., 2011; Tesli et al., 2011) and a series of 5′ SNPs, including rs10994336, rs10994397, and rs1938526 (Ferreira et al., 2008; Schulze et al., 2009; Scott et al., 2009; Sklar et al., 2011; Tesli et al., 2011) that are in linkage disequilibrium (LD) and represent a single association signal(Sklar
