The reference OMIM entry for this protein is 262850

Alpha-2-plasmin inhibitor deficiency
Antiplasmin deficiency
Plasmin inhibitor deficiency

A number sign (#) is used with this entry because alpha-2-plasmin inhibitor deficiency is caused by mutation in the PLI (SERPINF2; 613168) gene.

DESCRIPTION

Alpha-2-plasmin inhibitor deficiency is a rare autosomal recessive hemorrhagic diathesis. Most bleeds are severe, appear during childhood, and, in a few cases, umbilical bleeding is the first manifestation. Some homozygous patients present only moderate bleeding (Favier et al., 2001).

CLINICAL FEATURES

An inherited hemorrhagic diathesis due to plasmin inhibitor deficiency was described by Koie et al. (1978) in a 25-year-old Okinawa man. He had suffered prolonged bleeding and ecchymoses after minor trauma, spontaneous joint hemorrhage, and one episode of hemothorax. The bleeding episodes were reduced in frequency and severity by an antiplasminic drug. Laboratory abnormalities were limited to shortened euglobulin-lysis time and whole blood clot lysis time. No circulating alpha-2-plasmin inhibitor was found in the plasma. Even though only one case was observed, autosomal recessive inheritance was undoubted because the parents were consanguineous and both had plasma antiplasmin levels about half normal. The authors called the condition Miyasato disease after the proband's surname. The same patient was reported by Aoki et al. (1979). Kluft et al. (1979) reported an apparent homozygote, a 17-year-old boy with unrelated parents and a severe hemorrhagic diathesis. In a full report, Kluft et al. (1987) reported that a younger sister was likewise an apparent homozygote and that 8 heterozygotes were identified by half-normal activities and normal antigen concentrations. The 2 homozygotes were found to have very low functional levels as determined by the immediate plasmin inhibition test but normal plasma concentrations of alpha-2-antiplasmin antigen. The abnormal alpha-2-antiplasmin was designated Enschede after the city of birth of the propositus. The abnormal antiplasmin molecule was defective in the plasmin inhibition test, but had normal plasminogen-binding properties. Favier et al. (2001) stated that a notable clinical feature is an unusual localization of bleeding, intramedullary hematoma in the diaphyses of long bones, which has been described in 4 cases (Takahashi et al., 1991; Devaussuzenet et al., 1998). Radiography indicated homogeneous hyperlucent lesions with regular limits and without marginal sclerosis, which can be difficult to distinguish from cystic fibrous dysplasia, Langerhans cell histiocytosis, or metastasis of neuroblastoma. Accurate diagnosis of these intramedullary hematomas can be achieved with magnetic resonance imaging, however. Similar bone hematomas have been described in afibrinogenemia cases (Lagier et al., 1980).

DIAGNOSIS

Favier et al. (2001) stated that no simple coagulation assay points to the diagnosis of PLI deficiency. Therefore, a specific PLI assay should be performed when a patient has a bleeding diathesis that the usual screening tests do not identify.

INHERITANCE

Congenital deficiency of alpha-2-plasmin inhibitor is a rare autosomal recessive disorder. Favier et al. (2001) noted that some heterozygotes have bleeding complications, and the bleeding tendency may increase with age (Ikematsu et al., 1996).

MOLECULAR GENETICS

In the patient with inherited hemorrhagic diathesis due to plasmin inhibitor deficiency described by Koie et al. (1978), Miura et al. (1989) identified homozygosity for a mutatio ... More on the omim web site

Subscribe to this protein entry history

June 29, 2020: Protein entry updated
Automatic update: OMIM entry 262850 was added.

Feb. 22, 2019: Protein entry updated
Automatic update: comparative model was added.

Feb. 22, 2019: Protein entry updated
Automatic update: model status changed

Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).