Other names: Plasminogen Deficiency Type 1

Hypoplasminogenemia (Plasminogen Deficiency Type 1) is a genetic condition characterized by thick growths on the mucous membranes of the body.

Hypoplasminogenemia is caused by alterations in the plasminogen (PLG) gene, which leads to a deficiency of the enzyme plasminogen. 

Plasminogen is a naturally occurring protein that is synthesized by the liver and circulates in the blood. Activated plasminogen, known as plasmin, is the main enzyme involved in fibrinolysis, which is the breakdown of fibrin. Fibrin is an important protein in blood clotting and wound healing. When there are reduced levels of plasminogen, fibrin abnormally accumulates in the body, causing local inflammation and the development of ligneous growths that have a texture that resembles wood.

 The most common mucous membranes affected are the conjunctiva (the membrane that lines the eyes) and the gingiva (gums).

When the growths affect the conjunctiva, the condition is called ligneous conjunctivitis. The lesions can cause damage to the cornea, and can lead to a loss of vision. When the gums are affected, the condition is called ligneous gingivitis. These growths are not usually painful, but can lead to a loss of gum tissue and potentially a loss of teeth. 

Other mucous membranes that can be affected include those lining the nose, middle ear, stomach and intestines (gastrointestinal tract), respiratory tract and the female genital tract. The disorder can also affect the kidneys and the brain.

The first FDA approved treatment for hypoplasminogenemia is Ryplazim (plasminogen, human-tvmh). Ryplazim works by increasing the plasma level of plasminogen, temporarily correcting the deficiency and reducing or resolving lesions.

Drugs used to treat Hypoplasminogenemia