Candidate gene and whole-genome linkage analyses on alcoholism and antisocial alcoholism (alcoholism plus antisocial personality disorder or intermittent explosive disorder) were performed in population isolates consisting of Finnish families, among whom probands were alcoholic offenders, and also in a large Southwestern American Indian family (Reich et al 1998; Nurnberger et al 2002). Results included strong evidence for genetic influences in antisocial alcoholism. Linkage was found at chromosomes 11p (location of DRD2 dopamine receptor), 4p (GABAA cluster), and 4q (ADH cluster), as well as sibpair linkage to the 5HT1B receptor gene previously implicated by mouse 5HT1B knockout studies (Adamson et al 1995). In recent years, there also have been indications that two serotonin genes, 5-HT1B and tryptophan hydroxylase (TPH), may be linked to the impulsive or antisocial dimensions of behavior in alcoholics (Lappalainen et al 1998; Nielsen et al 1998; Kühn et al 1999).
