To cite this article: Rodrigues CA, Rocha LKA, Morelli VM, Franco RF, Lourenç o DM. Prothrombin G20210A mutation, and not factor V Leiden mutation, is a risk factor for cerebral venous thrombosis in Brazilian patients. J Thromb Haemost 2004; 2: 1211-12. Prothrombin G20210A mutation, factor (F)V Leiden mutation and oral contraceptive (OC) use were previously shown to be associated with an increased risk of cerebral venous thrombosis (CVT) [1][2][3]. We investigated the prevalences of prothrombin G20210A mutation, FV Leiden mutation and OC use in 42 consecutive patients with objectively confirmed diagnosis of CVT (median age of 28 years and 67% being women), and compared them with 134 healthy subjects, recruited from biologically unrelated acquaintances or partners of patients without history of venous thromboembolism (VTE) or known systemic diseases (median age of 34 years and 60% being women).Prothrombin G20210A mutation was found in 16.7% of patients and 0.7% of the control group, yielding an odds ratio (OR) for CVT of 26.6 [95% confidence interval (CI): 3.2-223.5]. FV Leiden mutation was detected in 4.8% of patients and in 2.2% of the control group (OR: 2.2, 95% CI: 0.4-13.5). It is noteworthy that the majority of carriers of prothrombin G20210A mutation and FV Leiden mutation were Caucasian.Our prevalence of prothrombin G20210A mutation was similar to an Italian study (20%) [3], and to a previous Brazilian report with 14 CVT patients (14.3%) [4]. In accordance to previous reports [2,3], prothrombin G20210A mutation was a significant risk factor for CVT. The proportion of patients carrying FV Leiden was also similar to the previous Brazilian report (7.1%) [4], but lower as compared with the Italian series (15%) [3]. The high prevalence of the prothrombin G20210A mutation in Brazilian patients may derive from the ethnic background of the study populations. Brazilian general population has an extremely heterogeneous ethnic composition, unevenly distributed in the country with variable degrees of admixtures. Brazilian citizens of Caucasian descent originate mainly from Southern Europe (specially Portugal, Italy and Spain), where prevalence of the prothrombin G20210A mutation is twice as high as compared to Northern Europe [5]. Patients and controls had a heterogeneous ethnic distribution: among patients, 55% were Caucasians and 43% were of Caucasian and Black descent and among controls, 20% were Caucasians and 80% were of Caucasian and Black descent. It is important to point out that the high OR for the prothrombin G20210A mutation may be in part attributable to the relatively low frequency of Caucasians among controls, since carriers of prothrombin G20210A mutation were in general Caucasians.Eighty-nine percent of women had thrombosis between 20 and 50 years of age (Fig. 1). For this age group, 60% of the patients were OC users and 20% were in the puerperium when CVT was diagnosed. Among the five women with inherited thrombophilia, there were four who were also OC users. Among patients, 60% were OC users as c...
