High molecular weight kininogen deficiency

High Molecular Weight Kininogen Deficiency (HMWKD) is a rare blood disorder characterized by a deficiency of the protein known as high molecular weight kininogen (HMWK). This protein plays a crucial role in the blood coagulation process and its deficiency can lead to abnormal bleeding.

Overview

High molecular weight kininogen (HMWK) is a protein that is part of the kinin-kallikrein system, which is involved in blood coagulation, inflammation, and blood pressure regulation. HMWK is produced in the liver and circulates in the bloodstream. It is a precursor to bradykinin, a potent vasodilator.

Causes

High Molecular Weight Kininogen Deficiency is an autosomal recessive disorder, which means that an individual must inherit two copies of the defective gene, one from each parent, in order to develop the disorder. The condition is caused by mutations in the KNG1 gene, which provides instructions for making HMWK.

Symptoms

The primary symptom of HMWKD is a prolonged bleeding time, which can lead to excessive bleeding after injury or surgery. Other symptoms may include easy bruising, nosebleeds, and heavy menstrual periods in women.

Diagnosis

Diagnosis of HMWKD is based on laboratory tests that measure the levels of HMWK in the blood. These tests include coagulation tests such as the activated partial thromboplastin time (aPTT) test, which is prolonged in individuals with HMWKD.

Treatment

There is currently no specific treatment for HMWKD. Management of the disorder primarily involves preventing and treating bleeding episodes. This may include the use of antifibrinolytic drugs to prevent bleeding, and blood transfusions to replace lost blood.

See also

• Blood disorders
• Coagulation
• Kinin-kallikrein system
• Bradykinin
• KNG1

NIH genetic and rare disease info

• NIH info on High molecular weight kininogen deficiency

High molecular weight kininogen deficiency is a rare disease.