Because of possible associations between these SNPs and nicotine dependence, we also evaluated whether mean cigarettes smoked per day varied by genotype. White cases carrying the variant allele at any of the three SNPs reported significantly higher numbers of cigarettes smoked per day than white cases carrying major alleles (Table 5). A similar association was not seen in white controls. Cigarettes smoked per day did not vary significantly by genotype in African American cases or controls.
