Inflammatory bowel diseases are not associated with major hereditary conditions predisposing to thrombosis

Patients with inflammatory bowel diseases (IBD) are at increased risk for t hromboembolic complications. Our aim was to evaluate whether the increased risk for thrombosis in IBD could be due to a genetic association of IBD wit h hereditary prothrombotic conditions. In all, 102 IBD patients (51 with ul cerative colitis and 51 with Crohn's disease) with no history of thrombosis and 204 matched normal subjects were enrolled, DNA specimens were evaluate d by PCR and restriction fragment length polymorphism for factor V Leiden, methylene tetrahydrofolate reductase (MTHFR) and prothrombin gene mutations , In IBD patients and matched controls the observed allele frequencies were similar, being 1.5% and 1.2% for factor V Leiden gene mutation, 1.1% and 0 .7% for prothrombin gene mutation, and 45.1% and 47.4% for MTHFR gene mutat ion, respectively. These rates also were not significantly different when p atients were analyzed according to age and sex distribution, diagnosis, and extension and clinical typo of disease. In conclusion, our study shows no association between IBD and the most frequent hereditary prothrombotic cond itions. Other factors should be evaluated in order to understand the mechan isms underlying the thrombotic risk of IBD.