significantly associated with both SI and ND. Since the frequency of the minor haplotype is relatively low (0.013–0.026), there is a chance that this haplotype may be an artifact of the haplotype reconstruction program. It is well known that haplotypes with low frequencies have much higher error rate. On the other hand, the association of the major haplotype 1-2-1 is likely true. In fact, this haplotype remains significant when we restrict the analyses to those haplotypes observed at least once in our data (frequencies were 0.370 and 0.311 for the smokers and non-smokers, and P = 0.04084). This haplotype seems to extend to the first exon, carrying the A allele (Asn) of the Asp40Asn polymorphism.
