When a coagulation defect was present (ie, the 20210 AG prothrombin genotype or the factor V Leiden mutation), the risk of myocardial infarction for carriers versus noncarriers was 1.4 (95% CI, 0.9 to 2.2).
When a coagulation defect was present (ie, the 20210 AG prothrombin genotype or the factor V Leiden mutation), the risk of myocardial infarction for carriers versus noncarriers was 1.4 (95% CI, 0.9 to 2.2).
We studied 609 patients with venous thromboembolism (287 with factor V Leiden, and 322 with prothrombin 20210A), 174 patients with myocardial infarction (78 with factor V Leiden, and 96 with prothrombin 20210A), and 198 controls (96 with factor V Leiden, and 102 with prothrombin 20210A).
We report a case of myocardial infarction at a young age in a subject heterozygous for the G20210Aprothrombin gene variant and homozygous for the C677T MTHFR polymorphism, who presented a strong family history of atherothrombosis.
We investigated the relationship between polymorphisms in the Factor V (Leiden), prothrombin (20210 GgA) and thrombomodulin (Ala455Val) genes in patients with a myocardial infarction (MI) <45 years of age (n=195) and in unaffected siblings (n=107) and unrelated healthy race-matched individuals drawn from the same community (n=300).
To investigate the association between the risk of myocardial infarction at a young age and genetic factors thought to be associated with an increased tendency to thrombosis (the polymorphisms 4G/5G of the PAI-1 gene, PIA1/PIA2 of the platelet glycoprotein IIIa, C3550T of the platelet glycoprotein Ib gene, G10976A of the factor VII gene, C677T of the methylenetetrahydrofolate reductase gene, G1691A of the factor V gene, and G20210A of the prothrombin gene), we performed a case-control study evaluating 200 survivors (185 men, 15 women) of myocardial infarction who had experienced the event before the age of 45 years and 200 healthy subjects with a negative exercise test, individually matched for sex, age, and geographic origin with the cases.
These preliminary results suggest that common genetic variants in the prothrombin gene or other variants in linkage disequilibrium are associated with myocardial infarction in postmenopausal women.
These data suggest that being heterozygote for the allele variant 20210A of the prothrombin gene could be a genetic risk factor for developing myocardial infarction.
The very low prevalence of the A allele indicates that the prothrombin variant is not a major cause of venous thrombosis or myocardial infarction in blacks.
The mutation was not more frequent among patients with a history of myocardial infarction (2.2%, odds ratio 0.7; 95% confidence interval 0.27 to 2.05), and there was no evidence of an interaction between the prothrombin mutation and conventional cardiovascular disease risk factors.
The frequency of heterozygotes for the 20210A prothrombin allele was 6.5% among patients and 2.8% among controls (OR 2.4, 95% CI 1.0-5.9), increasing to 8.7% in patients with a family history of myocardial infarction (OR 3.3, 95% CI 1.2-9.1), to 9.9% in patients (n=81) with < or =1 vessel disease (OR 3.8, 95% CI 1.3-10.8), and to 13.0% in patients who were normocholesterolaemic, non-diabetic, normotensive and non-smokers (OR 5.1, 95% CI 1.2-21.4).
The frequencies of factor V Leiden and prothrombin variant G20210A were determined in 41 patients age <50 years who had "normal" or "near normal" coronary arteries (no stenosis >50%) at angiography three to four weeks after MI (the study group) and compared with those in 114 patients who had at least one angiographic stenosis >50% after MI (the control group).
The factor V Leiden and prothrombinG20201A mutations did not significantly correlate with myocardial infarction (OR 1.26, 95% CI 0.94 to 1.67, P=0.12 and OR 0.89, 95% CI 0.59 to 1.35, P=0.6, respectively).
The prothrombin mutation is a mild risk factor for VTE within families of carriers but does not seem to play an important role in arterial thrombotic disease, with the exception ofmyocardial infarction, or in pregnancy-related complications.
Smoking (OR, 2.48; 95 % CI, 1.20-5.15), the A1691 mutation in factor V gene (OR, 3.64; 95 % CI, 1.31-10.10), and the A20210 mutation in the prothrombin gene (OR, 8.40; 95 % CI 3.35-21.05) were associated with FH of premature stroke (n = 33), while circulating anti-phospholipids to FH of premature myocardial infarction (n = 45; OR, 3.48; 95 % CI, 1.61-7.51).
It is evident that neither the Factor V Leiden mutation nor the 20210 A prothrombin mutation is a major risk factor for myocardial infarction or stroke, unless accompanied by other classical risk factors, including diabetes mellitus, hypertension and smoking.
In this study, we proposed to determine the prevalence of 20210A prothrombin variant among Tunisian population, and to evaluate the potential relevance of this variant with myocardial infarction.