[Molecular biological approach for congenital abnormality of blood coagulation].

Proteins of blood coagulation are categorized into three major groups, coagulation proteins, regulatory proteins and fibrinolytic proteins, in terms of their physiologic functions. Congenital deficiencies or abnormalities of these proteins elicit bleeding or thrombotic disorders. In general, defects of coagulation proteins are associated with a predisposition to bleeding disorders. By contrast, both defects of regulatory and fibrinolytic proteins are associated with a predisposition to thrombosis. The marked advances in molecular biology in the 1980s has allowed us to detect gene defects in most patients with congenital bleeding or thrombotic disorders. The information has contributed to our understanding of the structure and function relationship of the blood coagulation proteins. We have reported patients with congenital deficiencies or abnormalities of blood coagulation proteins. Herein, we describe the general approach for elucidating gene defects in patients with congenital bleeding or thrombotic disorders and provide a case of a Japanese family with congenital plasminogen deficiency in whom the genetic abnormality was identified.