Presence of a single ALDH2*2 allele is protective against heavy drinking and alcohol dependence in a semi-dominant manner (Crabb et al., 1989). People carrying even one ALDH2*2 allele can have blood acetaldehyde levels of 30 – 75 μM or higher, more than 10 times the normal level (Peng et al., 2014a, Harada et al., 1983, Adachi et al., 1989). This causes a severe form of flushing that includes increased skin temperature, nausea, vomiting, headaches, and increased pulse rate (Goedde et al., 1979, Goedde et al., 1983, Harada et al., 1981, Mizoi et al., 1983, Shibuya et al., 1989). The effects are similar to those of disulfiram (Antabuse®), a drug approved for treatment of AUD. This aversive reaction reduces the propensity to drink, the amount consumed per occasion, and thereby the risk for alcoholism (Bosron and Li, 1981, Harada et al., 1982, Thomasson et al., 1991, Hurley et al., 2002, Edenberg, 2007, Crabb et al., 1989, Chen et al., 2009, Luczak et al., 2006, Goedde et al., 1992, Edenberg, 2012, Chen et al., 1999b, Whitfield, 2002, Hurley and Edenberg, 2012). In
