Influences of polymorphic variants of DRD2 and SLC6A3 genes, and their combinations on smoking in Polish population

Table 3 Numbers and frequencies of DRD2/SLC6A3 combinations, and odds ratios for these genotype combinations for separate smoking phenotypes

Genotype combinations	Light/Heavy smoking No. (%)		OR (95% CI) p-value	Early/late start of smoking No. (%)		OR (95% CI) p-value
	≤10 cig./day	>10 cig./day		Before 20 year of life	In/after 20 year of life
A1+/9+	9 (52.9)	8 (47.1)	1^†	4 (23.5)	13 (76.5)	1^†
A1+/9-	5 (18.5)	22 (81.5)	4.95 (1.22-20.08) 0.017*	13 (48.1)	14 (51.9)	3.02 (0.75-12.13) 0.096*
A1-/9+	9 (20)	36 (80)	4.5 (1.32-15.32) 0.013*	16 (35.6)	29 (64.4)	1.79 (0.49-6.59) 0.357*
A1-/9-	7 (11.5)	54 (88.5)	8.68 (2.47-30.46) 0.0005*	32 (52.5)	29 (47.5)	3.79 (1.03-13.90)^†† 0.003*
Females						1.33 (0.20-8.70) 0.865**
Males						7.64 (1.29-45.15) 0.007**

^†OR = 1 for genotype combination related to the lowest frequency of given smoking-related phenotype
^††sex-adjusted OR
*significance level after Bonferroni correction: p = 0.05/2 = 0.025
**significance level after Bonferroni correction: p = 0.05/3 = 0.017

ISSN: 1471-2350