Complete plasminogen activator inhibitor 1 deficiency (complete PAI-1 deficiency) is a disorder that causes abnormal bleeding. In people with this disorder, bleeding associated with injury can be excessive and last longer than usual.

Individuals with complete PAI-1 deficiency may experience prolonged nosebleeds, excessive bleeding after medical or dental procedures, easy bruising, and significant bleeding into the joints or soft tissues after even a minor injury. Internal bleeding after an injury, especially bleeding around the brain (intracranial hemorrhage), can be life-threatening. Affected females may have excessive bleeding associated with menstruation (menorrhagia) and abnormal bleeding in pregnancy and childbirth.

In addition to bleeding problems, some people with complete PAI-1 deficiency develop scar tissue in the heart (cardiac fibrosis), which can lead to heart failure.

Complete PAI-1 deficiency is a rare disorder; its prevalence is unknown. It has been well studied in a large family belonging to the Old Order Amish population of eastern and southern Indiana. Additional cases in North America, Europe, and Asia have been described in the medical literature.

Complete PAI-1 deficiency is inherited equally by both sexes, but tends to be diagnosed earlier and more frequently in females because of its effects on menstruation, pregnancy, and childbirth.

Complete PAI-1 deficiency is caused by mutations in the SERPINE1 gene. This gene provides instructions for making a protein called plasminogen activator inhibitor 1 (PAI-1). PAI-1 is involved in normal blood clotting (hemostasis). After an injury, clots protect the body by sealing off damaged blood vessels and preventing further blood loss.

The PAI-1 protein blocks (inhibits) the action of other proteins called plasminogen activators. These proteins promote the dissolution of clots (fibrinolysis). By inhibiting plasminogen activators, the PAI-1 protein helps ensure that clots remain intact until they are no longer needed to stop bleeding.

The SERPINE1 gene mutations that cause complete PAI-1 deficiency result in the production of a PAI-1 protein that is nonfunctional or that is unstable and quickly broken down. Absence of functional PAI-1 protein allows plasminogen activators to dissolve blood clots prematurely, resulting in the abnormal bleeding associated with this disorder.

Genetic Testing Information

• Genetic Testing Registry: Congenital plasminogen activator inhibitor type 1 deficiency

Genetic and Rare Diseases Information Center

• Congenital plasminogen activator inhibitor type 1 deficiency

Patient Support and Advocacy Resources

• National Organization for Rare Disorders (NORD)

Catalog of Genes and Diseases from OMIM

• PLASMINOGEN ACTIVATOR INHIBITOR-1 DEFICIENCY

Scientific Articles on PubMed

• PubMed

• Fay WP, Parker AC, Condrey LR, Shapiro AD. Human plasminogen activator inhibitor-1 (PAI-1) deficiency: characterization of a large kindred with a null mutation in the PAI-1 gene. Blood. 1997 Jul 1;90(1):204-8. Citation on PubMed
• Flevaris P, Vaughan D. The Role of Plasminogen Activator Inhibitor Type-1 in Fibrosis. Semin Thromb Hemost. 2017 Mar;43(2):169-177. doi: 10.1055/s-0036-1586228. Epub 2016 Aug 24. Citation on PubMed
• Heiman M, Gupta S, Lewandowska M, Shapiro AD. Complete Plasminogen Activator Inhibitor 1 Deficiency. 2017 Aug 3 [updated 2023 Feb 23]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2025. Available from http://www.ncbi.nlm.nih.gov/books/NBK447152/ Citation on PubMed
• Heiman M, Gupta S, Shapiro AD. The obstetric, gynaecological and fertility implications of homozygous PAI-1 deficiency: single-centre experience. Haemophilia. 2014 May;20(3):407-12. doi: 10.1111/hae.12313. Epub 2013 Nov 22. Citation on PubMed
• Jankun J, Skrzypczak-Jankun E. Plasminogen activator inhibitor with very long half-life (VLHL PAI-1) can reduce bleeding in PAI-1-deficient patients. Cardiovasc Hematol Disord Drug Targets. 2013 Aug;13(2):144-50. doi: 10.2174/1871529x11313020007. Citation on PubMed
• Mehta R, Shapiro AD. Plasminogen activator inhibitor type 1 deficiency. Haemophilia. 2008 Nov;14(6):1255-60. doi: 10.1111/j.1365-2516.2008.01834.x. Citation on PubMed
• Minowa H, Takahashi Y, Tanaka T, Naganuma K, Ida S, Maki I, Yoshioka A. Four cases of bleeding diathesis in children due to congenital plasminogen activator inhibitor-1 deficiency. Haemostasis. 1999;29(5):286-91. doi: 10.1159/000022514. Citation on PubMed
• Takahashi Y, Tanaka T, Minowa H, Ookubo Y, Sugimoto M, Nakajima M, Miyauchi Y, Yoshioka A. Hereditary partial deficiency of plasminogen activator inhibitor-1 associated with a lifelong bleeding tendency. Int J Hematol. 1996 Jul;64(1):61-8. doi: 10.1016/0925-5710(96)00460-4. Citation on PubMed
• Yasar Yildiz S, Kuru P, Toksoy Oner E, Agirbasli M. Functional stability of plasminogen activator inhibitor-1. ScientificWorldJournal. 2014;2014:858293. doi: 10.1155/2014/858293. Epub 2014 Oct 15. Citation on PubMed or Free article on PubMed Central
• Zhang ZY, Wang ZY, Dong NZ, Bai X, Zhang W, Ruan CG. A case of deficiency of plasma plasminogen activator inhibitor-1 related to Ala15Thr mutation in its signal peptide. Blood Coagul Fibrinolysis. 2005 Jan;16(1):79-84. doi: 10.1097/00001721-200501000-00013. Citation on PubMed