48 This SNP encodes an amino acid substitution, replacing asparagine (N40) with aspartate (D40), thus removing a potential glycosylation site. Although the involvement of A118G in AUD has been controversial, 49 , 50 , 51 and there was no significant association with risk for alcoholism in a COGA family‐based study, 52 its role in opioid dependence has been established in both mouse and human contexts. Studies found that human GABA inhibitory induced neurons (iNs) derived from iPSCs generated from individuals of European descent show stronger inhibition of synaptic transmission in D40, as compared with N40 neurons. 46 Similar changes in synaptic transmission were observed in CRISPR‐edited, isogenic lines containing N40 or D40 variants, ruling out possible differences due to genetic backgrounds in different participants. 46
