Association between Genetic Variants on Chromosome 15q25 Locus and Several Nicotine Dependence Traits in Polish Population: A Case-Control Study

Table 2

Association between genotypes and smoking-related phenotypes.

SNP	Smoking initiation			Age at onset of daily smoking			CPD			FNTD
	Never	Ever	OR (95% CI)	≤16 years	>16 years	OR (95% CI)	<20	≥20	OR (95% CI)	<4	≥4	OR (95% CI)
16969868^a-1051730^a
AA + AG	88	123	1.39 (0.93–2.02)	20	103	1.04 (0.49–2.18)	35	52	2.66 (1.30–5.42)^*	21	66	2.60 (1.24–5.43)^**
588765^b
TT + TC	129	151	0.92 (0.59–1.44)	27	123	0.69 (0.29–1.63)	51	50	0.84 (0.39–1.78)	35	66	0.65 (0.28–1.49)
6495308^c
CC + CT	75	73	0.71 (0.47–1.07)	12	61	1.01 (0.46–2.23)	27	20	0.61 (0.30–1.25)	16	30	0.84 (0.39–1.78)
578776^a
AA + AG	85	87	0.68 (0.45–1.05)	15	72	1.09 (0.52–2.29)	32	26	0.67 (0.34–1.32)	19	38	0.91 (0.44–1.92)

FNTD: Fagerström Test for Nicotine Dependence; CPD: cigarettes per day.
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Genotype frequencies were corrected for multiple comparisons using the Bonferroni method. We analyzed rs16969968 and rs1051730 together because they stay in perfect linkage disequilibrium block. So the threshold value was obtained by dividing 0.05 by 4; thus, threshold value = 0.0125.
^aRisk (minor) allele A.
^bRisk (minor) allele T.
^cRisk (minor) allele C.