Location and extent of deep vein thrombosis in patients with and without FV : R 506Q mutation

Resistance to activated protein C due to FV:R 506Q mutation is the most com mon known genetic risk factor for deep leg vein thrombosis (DVT). The aim o f this prospective study was to describe and compare the location and exten t of DVT, reflected by a scoring system, in a group of patients with and wi thout FV:R 506Q mutation. Of 247 consecutively included patients undergoing phlebography 105 had a DVT, 36 (35%) in the FV:R 5064 mutation group and 6 9 (65%) in the non-FV:R 506Q mutation group. Compared to the non-FV:R 506Q mutation group there was a significant increase in the incidence of DVT in the FV:R 506Q mutation group (p = 0.041, OR = 1.79 [1.02-3.15]), a signific antly lower mean DVT score of the iliofemoral vein segments (p = 0.0081) an d a significantly lower incidence of DVT in the iliofemoral vein segments ( p = 0.007, OR = 10.6 [1.3-83.3]), 1/36 (2.8%) compared to 16/69 (23.2%). As controls 288 blood donors were included, with and without FV:R 5064 mutati on and with no history of DVT in order to evaluate risk factors of DVT. The odds ratio of an iliofemoral DVT was 0.5 ([0.06-3.90), p = 0.50]) when FV: R 506Q mutation was present, compared to the control group, and at location s below the iliofemoral segments 5.28 ([3.01-9.28], p = less than 0.0001). Our findings provide the basis of a detailed phlebographic description and for the first time, to our best knowledge, shows a specific phlebographic p attern that may be linked to an inherited hypercoagulable state.