Due to the association between current smoking status and SNPs in GABRA2, we also conducted haplotype tests on the unrelated MZ case-control sample (dropping haplotypes with frequencies < 0.01). Sliding windows revealed the most significant 2-SNP haplotype (p = 0.01) to be between rs2165250 and rs279858 with overtransmission of T-G (64%) to the controls. Haplotype association with the 7-SNP haplotype showed evidence for overtransmission of the T-T-G-A-T-T-T (63%) to the controls/ex-smokers and of the complementary C-C-A-T-C-C-C (47%) to the cases/current smokers was noted (global p-value of 0.03) where the rs279845 and rs279826 alleles are highlighted in bold.
