Genetic Risk Factors Associated With Antiphospholipid Antibody Syndrome

Antiphospholipid antibody syndrome (APS) is characterized by the presence of antiphospholipid antibodies, which are proteins in the blood that interfere with the body's ability to perform normal blood clotting. Clinical problems associated with antiphospholipid antibodies include an increased risk for the formation of blood clots in the lungs or deep veins of the legs, stroke, heart attack, and recurrent miscarriages. It is possible that some people with APS have a genetic predisposition for developing the syndrome. This study will use a genetic strategy to identify potential inherited risk factors for the development of APS by recruiting people with APS who have family members also affected by the syndrome or by another autoimmune disorder, such as lupus or rheumatoid arthritis.