Aggregation absent/severely decreased with all agonists (arachidonic acid, ADP, collagen, TRAP), except ristocetin (reduced but not absent). This pattern, perhaps less severe, can be seen in cases of dominant thrombocytopenia due to mutations in the Glanzmann genes (ITGA2B and ITGB3). This evidence concerns the gene ITGA2B and Thrombocytopenia.