Glanzmann thrombasthenia is a bleeding disorder that is characterized by prolonged or spontaneous bleeding starting from birth. People with Glanzmann thrombasthenia tend to bruise easily, have frequent nosebleeds (epistaxis), and may bleed from the gums. They may also develop red or purple spots on the skin caused by bleeding underneath the skin (petechiae) or swelling caused by bleeding within tissues (hematoma). Glanzmann thrombasthenia can also cause prolonged bleeding following injury, trauma, or surgery (including dental work). Women with this condition can have prolonged and sometimes abnormally heavy menstrual bleeding. Affected women also have an increased risk of excessive blood loss during pregnancy and childbirth.

Mutations in the ITGA2B or ITGB3 gene cause Glanzmann thrombasthenia. These genes provide instructions for making the two parts (subunits) of a receptor protein called integrin alphaIIb/beta3 (αIIbβ3). This protein is abundant on the surface of platelets. Platelets are small cells that circulate in blood and are an essential component of blood clots. During clot formation, integrin αIIbβ3 helps platelets bind together. Blood clots protect the body after injury by sealing off damaged blood vessels and preventing further blood loss.

Glanzmann thrombasthenia is estimated to affect 1 in one million individuals worldwide, but may be more common in certain groups, including those of Romani ethnicity, particularly people within the French Manouche community.

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Published Date: September 01, 2015
Published By: National Institutes of Health