The purpose this study was to determine whether Arg353Gln and -323Del/Ins polymorphisms of factor VII (FVII) are related to blood pressure levels and hypertension. Subjects were drawn from the Stanislas Cohort, a longitudinal, familial French cohort examined twice since 1994. The "blood pressure study" included 1342 subjects free of medication use that could affect blood pressure. The "hypertension study" included 645 normotensive and 77 hypertensive adult subjects. Association with hypertension was also studied in 547 hypertensives enrolled in a clinical trial and in 624 normotensives drawn from the Stanislas Cohort. In the "blood pressure study," parents with the 353Gln or -323Ins allele had lower blood pressures than did noncarriers at each examination, independent of covariates (0.01< or =P< or =0.05, except for diastolic blood pressure [DBP] at baseline, where P=0.103). Similarly significant relations were observed in their offspring (P< or =0.05, except for systolic blood pressure [SBP] at 5 years, where P=0.186). In a representative subgroup of 267 individuals, the -323Del/Ins polymorphism was significantly associated with plasma FVII levels in both parents and offspring (P<0.001). FVII levels in plasma were significantly correlated with SBP and DBP in parents but not in offspring. After inclusion of both FVII levels and the -223Del/Ins in the same model in parents, only FVII levels remained significantly associated with SBP and DBP. The "hypertension study" revealed that the 353Gln and -323Ins alleles were related to decreased risk (odds ratio [OR]=0.554, 95% confidence interval [CI], 0.362 to 0.848, and OR=0.475, 95% CI, 0.299 to 0.755, respectively). These results suggest that the FVII gene may be a susceptibility locus for hypertension.