analysis revealed two loci that had a LOD score of 3.0 or above for the fronto-central scalp region on chromosomes 1p36.31-p36.22 and 6p21.1. Additionally, 4 locations were identified with LOD scores above 2.0 on chromosomes 4q22.1, 11p14.1, 14q32.2, 16q12.2 for the fronto-central location and one on chromosome 2p12 for the centro-parietal-occipital location. These results corroborate the importance of regions on chromosome 4 and 6 highlighted in prior segregation studies in this and other populations for alcohol dependence-related phenotypes, as well as areas that overlap with other substance dependence phenotypes identified in previous linkage studies. Notably, further research is needed to determine whether the described linkage peak on chromosome 4 can be explained by polymorphisms in GABRA2 as reported by COGA [40] or polymorphisms in another gene. Nonetheless, these results support the general use of EEG traits and specifically support EEG alpha recorded from fronto-central scalp areas as important endophenotypes for alcohol and other substance dependence [37-38].
