Two human studies have identified alcohol dependence QTLs (LODs >3) on the q-arm of human chromosome 1 (Dick et al., 2002; Hill et al., 2004). A third human QTL for tobacco usage has also been identified in this same region (Ehlers et al., 2006). This region of human chromosome 1 is primarily syntenic to mouse chromosomes 1 (distal) and 3 (Figure 2). Coincident reciprocal QTLs for ethanol consumption and acute withdrawal are identified on mouse chromosomes 1 and 3 (Hitzemann et al., 2009), but have not been fine-mapped. Buck et al. (1997, 2002) also identified robust QTLs for both acute and chronic ethanol withdrawal on distal chromosome 1 (Alcw1 and Alcdp1, respectively). Recently, the development and testing of a panel of interval-specific congenic strains for distal chromosome 1 delineated two QTLs within the starting Alcw1/Alcdp1 interval. The more proximal QTL affects ethanol withdrawal, but not pentobarbital or zolpidem withdrawal (Kozell et al., 2008), while the more distal QTL affects ethanol, pentobarbital, and zolpidem withdrawal (Kozell et al., 2009). Both of these QTLs are syntenic to human chromosome 1q23.2-1q23.3 (Figure 2).
