['The study aimed at investigating the independent and the combined effects of the two common genetic variants in the methylenetetrahydrofolate reductase (MTHFR) gene, 677C > T and 1298A > C, and their interaction with lifestyle factors on timing of menarche and natural menopause.', 'Postmenopausal women (N = 792) were assessed for the association of the two genetic variants with age at menarche (AM). A subsample of 578 of them who had a natural menopause were further investigated for the association of the two genetic variants with age at natural menopause (ANM). Genotyping was done by means of the TaqMan(®) allelic discrimination method. The effect of genetic variants and of lifestyle factors on AM and ANM were calculated by linear regression models.', 'The study revealed no association between the individual or combined effects of the two genetic variants and AM or ANM. The genetic variant 677C > T showed a significant interaction effect with duration of breastfeeding on ANM (p = 0.047).'] Is age at menarche and menopause associated with two common genetic variants in the methylenetetrahydrofolate reductase ( MTHFR ) gene?