identified in that American Indian community study with LOD scores that provide evidence for linkage for a severe cannabis use/antisocial subtype on chromosome 16 (@139 cM, LOD score = 4.4), and on chromosome 19 (@74 cM, LOD score = 6.4) [Ehlers et al., 2009]. There have also been some findings in genome scans for cannabis dependence and other drug use related phenotypes on chromosome 19. A region has been identified on chromosome 19 at 17 cM for early-onset cannabis use, and for frequency of use on chromosome 18, in a study of 2314 Australian families [Agrawal et al., 2008b]. A site on chromosome 4 for a cannabis problems factor score has been identified on chromosome 4 in the region of the gamma aminobutyric acid type A gene cluser with a LOD score of 2.2 in the Nicotine Addiction Genetics Project [Agrawal et al., 2008a].
