A recent study in a sample of Plains Indians showed association between eight SNPs located in the SGIP1 gene and resting theta electroencephalogram (EEG) power (Hodgkinson et al., 2010). This association appeared to generalize to alcohol use disorders, for which EEG power is a potential endophenotype.
We analyzed a large, diverse sample for replication of the association of these implicated SGIP1 SNPs (genotyped on the Illumina 1M platform) with alcohol dependence (N = 3988) and theta EEG power (N = 1066).
We found no evidence of association of the previously implicated SGIP1 SNPs with either alcohol dependence or theta EEG power (all p > 0.15) in the current sample.
The previously implicated SNPs located in SGIP1 showed no association with alcohol dependence or theta EEG power in the present sample of individuals with European and/or African ancestry. This failure to replicate may be the result of differences in ancestry between the current and original samples.
Keywords: alcoholism, electroencephalogram, candidate gene association study