The search yielded 470 references. After discarding overlapping references and those which clearly did not meet the criteria, 70 studies remained. These studies were then filtered to ensure conformity with our inclusion criteria. One study (Higuchi et al. 1995) was excluded because subjects in this study were included in another study (Higuchi et al. 1996b); three studies (Choi et al. 2006; Harada et al. 1999; Yang et al. 2007) were excluded because they were investigating other polymorphisms, such as 1951G/A, rather than the SNP considered here; two (Shimosegawa et al. 2008; Tsuchihashi-Makaya et al. 2009) because the criteria to define “alcoholic” patients were not eligible (i.e., drinking and smoking behavior was assessed on the basis of the lifestyle questionnaire self-administered by the subjects (Tsuchihashi-Makaya et al. 2009); and patients with alcohol consumption of more than 80 g/day for at least two years were classified as alcoholic chronic pancreatitis (Shimosegawa et al. 2008)); two (Hendershot et al. 2009; Segado Soriano et al. 2005) because the patients were described nonspecifically as “drinkers”, rather than “dependent” or “abusers”; one (Nanakorn et al. 1999)
