NIH

Zebra of the Week: Glanzmann thrombasthenia

March 9, 2026

Glanzmann thrombasthenia (GT) is a congenital platelet aggregation disorder marked by prolonged or spontaneous bleeding from birth. Affected individuals typically present with easy bruising, recurrent epistaxis, gingival bleeding, and petechiae or hematomas. Bleeding may be disproportionate after minor trauma or procedures, and women often experience heavy menstrual bleeding with heightened obstetric hemorrhage risk. Gastrointestinal bleeding occurs in about one‑quarter of cases, while intracranial hemorrhage and hemarthrosis are rare but serious. Severity varies widely, even within families, and spontaneous bleeding tends to become less frequent with age.

FDA recently granted Breakthrough Therapy designation to sutacimig, a subcutaneously administered bispecific antibody, for the prevention of bleeding episodes in patients with GT.

Sources:

(Accessed 2026, March 6). NIH Genetic and Rare Diseases Information Center (GARD). Glanzmann thrombasthenia. https://rarediseases.info.nih.gov/diseases/2478/glanzmann-thrombasthenia

(2026, March 5). Hemab Therapeutics. Hemab Therapeutics Receives FDA Breakthrough Therapy Designation for Sutacimig in Glanzmann Thrombasthenia [Press release]. https://www.hemab.com/news-items/hemab-therapeutics-receives-fda-breakthrough-therapy-designation-for-sutacimig-in-glanzmann-thrombasthenia