The prothrombin 20210A allele and its association with myocardial infarction

The relationship between the prothrombin (PT) 20210A allele and arterial di sease is controversial. We conducted a case-control study to assess its con tribution to risk of myocardial infarction (MI). Five hundred and thirty-ni ne acute MI patients and 498 control subjects aged <75 years were studied. Two percent of cases carried the PT20210A allele compared to 2.8% of contro ls. The odds ratio for MI was 0.72 (95% Cl0.32-1.60) indicating that the PT 20210A allele confers no increased risk for MI. Subgroup analysis showed no association between the PT20210A allele and either premature MI or MI in f emales. We conclude the PT20210A allele is not a risk factor far MI and sug gest that discrepancies in studies relating the PT20210A allele to MI may b e due to difficulties in estimating its low allelic frequency in the genera l population and thus random differences in the observed frequencies in the control populations studied.