“…22,23 Genetic variants affecting aIIb and b3 cytoplasmic domains that produce MTP show that the mutations result in an altered cytoskeletal architecture and reduced proplatelet formation. 2,13,24 Our ITGB3 L718del (with loss of synchronization between the intracytoplasmic tail of b3 with that of aIIb) resulted in moderate MTP, decreased activation of aIIbb3 at the platelet surface, and abnormally large a-granules and represents a novel phenotype. Large compound granules have recently been described in platelets as part of the exocytosis mechanism, 25 but in our case, the giant granules were not empty.…”