A Case of Chronic Thrombocytopenia in a 17-Year-Old Female

Roger Riley, MD, PhD; Asad Khan, MD; Shella Pai, MS, SH(ASCP); Laura Warmke, MD; Marcus Winkler, MD; William Gunning, PhD


Lab Med. 2019;50(4):406-420. 

In This Article


GPS is a rare, inherited PLT disorder characterized by an absence or marked deficiency of PLT α-granules. These granules contain PF4, fibronectin, Factor V, vWF, PLT-derived growth factors, thrombospondin, transforming growth factor beta (TGF-β), and other chemical compounds essential to blood clotting, inflammation, wound healing, and other processes. Clinically, patients with GPS have moderate thrombocytopenia and present with bleeding diathesis of variable severity. Light microscopy of the peripheral blood smear of a patient with GPS reveals enlarged, agranular PLTs with a gray appearance. EM is necessary to confirm the absence of α-granules and to differentiate GPS from pseudo-GPS and other inherited PLT-function disorders. The results of recent studies have shown that the most common autosomal recessive form of GPS occurs due to a mutation in the NBEAL2 gene.