GP1BA

GP1BA is a gene that in humans encodes the glycoprotein Ib (GP Ib) alpha chain, which is a member of the leucine-rich glycoprotein family. This protein is a component of the Glycoprotein Ib-IX-V complex, which is a platelet surface membrane glycoprotein complex that functions as a receptor for von Willebrand factor (VWF). The complete receptor complex includes noncovalent association of the alpha and beta subunits with the plasma membrane glycoprotein IX and the non-membrane glycoprotein V. Mutations in this gene are associated with Bernard-Soulier syndrome, Velocardiofacial syndrome, and Platelet-type von Willebrand disease.

Function

The GP1BA gene provides instructions for making a protein that is part of a complex known as the Glycoprotein Ib-IX-V complex. This complex is found on the surface of platelets, which are blood cell fragments that play a crucial role in blood clotting. The GP1BA protein, along with other proteins in the complex, binds to a protein called von Willebrand factor. This binding is essential for the adhesion of platelets to sites of blood vessel injury, a critical early step in the formation of a blood clot.

Clinical significance

Mutations in the GP1BA gene are associated with Bernard-Soulier syndrome, a rare disorder characterized by a low number of large platelets and a tendency to bleed easily. Mutations in this gene are also associated with Velocardiofacial syndrome, a condition characterized by a combination of medical problems that vary from child to child. These medical problems include heart defects, specific facial features, frequent infections, developmental delay, learning problems, and cleft palate. In addition, mutations in the GP1BA gene can cause Platelet-type von Willebrand disease, a condition characterized by moderate to severe bleeding.

See also

• Glycoprotein Ib-IX-V complex
• von Willebrand factor
• Bernard-Soulier syndrome
• Velocardiofacial syndrome
• Platelet-type von Willebrand disease