Genetic variation in the CHRNA4 gene, but not the CHRNB2 gene, showed nominal association with DSM-IV nicotinic dependence symptoms (Table 4). Analysis were performed on both genes using FBAT (Laird et al. 2000). When CHRNA4 was analyzed in the non-Hispanic EA CADD sample two SNPs (rs1044394 and rs1044396) were significant at an uncorrected p < 0.05. Permutation testing carried out using the min –p option in FBAT (Rakovski et al. 2007) indicated that the most significant statistic reached a suggestive p-value of p = 0.12 when corrected for multiple testing. When individuals who self-identified as Hispanic were included in the analysis, rs1044394 remained at a suggestive p = 0.063, while the p-value associated with rs1044396 increased to 0.171.
