Glanzmann thrombasthenia: integrin alpha IIb beta 3 deficiency.

Integrins, a family of noncovalently associated alpha beta heterodimeric adhesion receptors, are involved in a variety of pathological and physiological processes. The importance of integrins is evident in the severe pathogenic consequences of their congenital deficiencies: Glanzmann thrombasthenia (GT) and leukocyte adhesion deficiency. In this review, I have focused on GT, a rare autosomal recessive bleeding disorder characterized by the quantitative and/or qualitative abnormality of integrin alpha IIb beta 3 (glycoprotein IIb-IIIa). Molecular genetic analysis of GT, when caused by a quantitative abnormality of alpha IIb beta 3, provides important information regarding key structures for alpha IIb beta 3 biosynthesis. Of particular interest is GT when caused by a qualitative abnormality of alpha IIb beta 3 (GT variants). The analyses of GT variants provide new insight into the regulation of alpha IIb beta 3 function and the interaction between alpha IIb beta 3 and its ligands. This research could contribute to new and better alpha IIb beta 3 antagonists with minimal complications (such as bleeding and thrombocytopenia) for the prevention and treatment of pathological thrombosis.