Human platelet glycoprotein V (GP5) is a part of the Ib-V-IX system of surface glycoproteins that constitute the receptor for von Willebrand factor (VWF, MIM 613160) and mediate the adhesion of platelets to injured vascular surfaces in the arterial circulation, a critical initiating event in hemostasis. The main portion of the receptor is a heterodimer composed of 2 polypeptide chains, an alpha chain (GP1BA, MIM 606672) and a beta chain (GP1BB, MIM 138720), that are linked by disulfide bonds. The complete receptor complex includes noncovalent association of the alpha and beta subunits with platelet glycoprotein IX (GP9, MIM 173515) and GP5. Mutations in GP1BA, GP1BB, and GP9 have been shown to cause Bernard-Soulier syndrome (MIM 231200), a bleeding disorder (review by Lopez et al., 1998 [PubMed 9616133]).[supplied by OMIM, Nov 2010],
