Table 2. MTHFR variants in smokers and non-smokers.

all individuals (samples 1+2; n = 1060)
c.677C>T	CC	CT	TT	nominal regression
smokers (n = 699)	0.41	0.47	0.12	Chi2 = 5.5; p = 0.064
non-smokers (n = 361)	0.49	0.42	0.09
c.1298A>C	AA	AC	CC
smokers (n = 699)	0.46	0.43	0.11	Chi2 = 6.4; p = 0.040
non-smokers (n = 361)	0.53	0.38	0.10
c.677C>T;c.1298A>C	c.677CC;c.1298AA	c.677TT;c.1298AA or c.677CC;c.1298CC	all others
smokers (n = 699)	0.12	0.22	0.66	Chi2 = 15.8; p<0.001
non-smokers (n = 361)	0.21	0.19	0.60

Genotype frequencies concerning the two alleles MTHFR c.6777C>T and MTHFR c.1298A>C as well as the genotype frequencies resulting from the c.677C>T;c.1298A>C haplotypes.