Three case reports of inherited antithrombin deficiency in China: double novel missense mutations, a nonsense mutation and a frameshift mutation.

Antithrombin is a plasma protein critical to the regulation of coagulation. It plays a pivotal anticoagulant role by preventing the activation of procoagulant proteinases. Inherited and (or) acquired deficiency of AT is an established risk factor for venous thromboembolism. Sequencing analysis of SERPINC1 gene of three families revealed that Family I had double novel missense mutations (c.134G > A&c.342T > G), Family II had a nonsense mutation (c.770G > A) while Family III had a frameshift mutation (c.800-803del). In addition, all of them had a large number of carriers in their families what was very rare in China.