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Background: Prenatal exposure to maternal cigarette smoking (prenatal smoke exposure) had been associated with altered DNA methylation (DNAm) at birth., Objective: We examined whether such alterations are present from birth through adolescence., Methods: We used the Infinium HumanMethylation450K BeadChip to search across 473,395 CpGs for differential DNAm associated with prenatal smoke exposure during adolescence in a discovery cohort (n = 132) and at birth, during childhood, and during adolescence in a replication cohort (n = 447)., Results: In the discovery cohort, we found five CpGs in MYO1G (top-ranking CpG: cg12803068, p = 3.3 × 10-11) and CNTNAP2 (cg25949550, p = 4.0 × 10-9) to be differentially methylated between exposed and nonexposed individuals during adolescence. The CpGs in MYO1G and CNTNAP2 were associated, respectively, with higher and lower DNAm in exposed versus nonexposed adolescents. The same CpGs were differentially methylated at birth, during childhood, and during adolescence in the replication cohort. In both cohorts and at all developmental time points, the differential DNAm was in the same direction and of a similar magnitude, and was not altered appreciably by adjustment for current smoking by the participants or their parents. In addition, four of the five EWAS (epigenome-wide association study)-significant CpGs in the adolescent discovery cohort were also among the top sites of differential methylation in a previous birth cohort, and differential methylation of CpGs in CYP1A1, AHRR, and GFI1 observed in that study was also evident in our discovery cohort., Conclusions: Our findings suggest that modifications of DNAm associated with prenatal maternal smoking may persist in exposed offspring for many years-at least until adolescence.

Background: The authors investigated the acceptability to women of the preventive strategies available for dealing with hereditary breast/ovarian carcinoma in France, the United Kingdom, and Canada, countries selected because of their cultural differences. The authors aimed to discover the existence of specific factors that may affect acceptability of these preventative measures., Methods: A cross-sectional, multicenter survey was conducted in Marseilles, France (n = 141), in Manchester, England (n = 130), and in Montreal, Quebec (n = 84). All of the women attending cancer genetic clinics for the first time because of a family history of breast-ovarian carcinoma completed a self-administered questionnaire before their clinic consultation., Results: Variations in responses to different preventative options presented on the questionnaire were seen within the sample of patients considered as a whole. The highest levels of acceptability were obtained for mammographic screening (87%) and chemoprevention (58%). In contrast, prophylactic oophorectomy and prophylactic mastectomy were thought to be acceptable at an early age (before 35 years), an age associated with the highest prophylactic efficacy, by only 19% and 16% of the respondents, respectively. After multivariate adjustment, the statistical data showed that the British respondents were more in favor of oophorectomy (P < 0.0001) and more in favor of chemoprevention than the French (P < 0.001) and the Canadian respondents (P < 0.001). The British (overall adjusted response [OR(adj)] = 3.9; P < 0.001) and Canadian respondents (OR(adj) = 3; P < 0.01) were more in favor of prophylactic mastectomy than the French. The cumulated acceptability of mammography before the age of 40 years was found to be greater in the French (OR(adj) = 2.8; P < 0.01) and Canadian (OR(adj) = 3.1; P < 0.05) samples than in the British sample., Conclusion: These results demonstrated the existence of international variations in the acceptability of the preventive strategies available for women at risk for hereditary breast/ovarian carcinoma. Therefore, these results suggested that when establishing medical recommendations or planning public health interventions, physicians must integrate the population's perception of advantages and drawbacks with the patient's individual decision making., (Copyright 2001 American Cancer Society.)