Both twin and family studies suggest that OUD has strong genetic underpinnings, with estimates of heritability around 50%(Mistry et al., 2014). Genome-wide association studies (GWASs) and expression quantitative mapping have reported hits in KCNC1, KCNG2, CNIH3, OPRM1, RGMA and SLC30A9 from multiple independent datasets. Pathway analysis also suggests the involvement of potassium, calcium and long-term potentiation signaling pathways(Cheng et al., 2018; Gelernter et al., 2014; Hancock et al., 2015; Nelson et al., 2016; Polimanti et al., 2020; Zhou et al., 2019).
