Given a large heritability for AUDs, sevral studies were conducted to identify the specific genes or genetic variations associated with AUD or related traits[8, 20–22]. The gene identification efforts for AUDs can be divided into pre-GWAS and the GWAS era. The pre-GWAS era mainly focussed on genome-wide linkage and candidate gene studies[23, 23–26]. Although, during this period many genes were nominated as the causal factors, a few genes actually showed consistent evidence of an association with AUD[23, 27]. Even the initial GWAS studies suffered from low power due to smaller sample sizes and failed to identify credible evidence in favor of any particular gene[28–30]. Power of GWAS significantly improved in the past couple of years with the advent of large biobanks (UK Biobank) and the collaborative efforts of large consortiums (Psychiatric Genetics Consortium [PGC]). Following section will briefly describe the most successful and replicated findings in candidate gene studies before moving to recent advances in the field of AUD gene discovery.
