Three New Gene Variants Raise Blood Clot Risk by 180%

Venous blood clots represent one of the world's most common yet underrecognized causes of death, affecting over 10,000 Swedes annually with numbers rising as populations age. Swedish researchers at Lund University have now identified three new gene variants that dramatically increase blood clot risk by up to 180%, adding to our understanding of genetic factors like Factor V Leiden that contribute to thrombosis.

The study reveals that genetics explains nearly half of all venous thrombosis cases in Sweden. These clots form differently than arterial clots - instead of plaque rupture triggering platelet aggregation, venous clots develop when blood stagnates in leg veins, activating the coagulation system. When these clots break free and travel to the lungs, they cause potentially fatal pulmonary embolisms.

Beyond genetics, the research highlights surprising physical risk factors. Height significantly increases clot risk because blood must travel greater distances against gravity to return to the heart, while larger veins in tall people provide relatively less blood flow. Weight also matters substantially, as obesity impairs venous circulation and often correlates with sedentary behavior that allows blood to stagnate.

Unlike arterial disease, venous clots aren't linked to traditional cardiovascular risk factors like high blood pressure or cholesterol, since veins operate as low-pressure systems that don't develop atherosclerosis. This distinction is crucial for understanding prevention strategies. The findings suggest that genetic testing combined with assessment of physical characteristics could help identify high-risk individuals who might benefit from targeted prevention measures, particularly during periods of immobility or other triggering circumstances.