Qualitative Platelet DisordersDr.Ali Ibrahim

Inherited disorders of platelet functionAbnormalities of the platelet receptors for adhesive proteinsGP Ib-V-IX complex (BernardSoulier syndrome, platelet-type von Willebrand disease, BolinJamieson syndrome)GP IIb/IIIa ) (Glanzmanns thrombasthenia)GP Ia/IIa (a2/b1)GPVIGPIVAbnormalities of the platelet receptors for soluble agonistsThromboxane A2 receptora2-adrenergic receptorP2Y12 receptorAbnormalities of the platelet granulesd-granules (d-storage pool deficiency, HermanskyPudlak ssyndrome, ChediakHygashi syndrome, thrombocytopenia with absent radii syndrome,WiskottAldrich syndrome)a-granules (gray platelet syndrome, Quebec platelet disorder, ParisTrousseauJacobsen syndrome)a- and d-granules (a,d-storage pool deficiency)

Abnormalities of the signal-transduction pathwaysAbnormalities of the arachidonate/thromboxane A2 pathwayGaq deficiencyPartial selective PLC-b2 isozyme deficiencyDefects in pleckstrin phosphorylationDefective Ca2 mobilizationHyperresponsiveness of platelet GsaAbnormalities of membrane phospholipidsScott syndromeStormorken syndromeMiscellaneous abnormalities of platelet functionPrimary secretion defectsOther platelet abnormalities (Montreal platelet syndrome, osteogenesis imperfecta, EhlersDanlos syndrome, Marfans syndrome, hexokinasedeficiency, glucose-6-phosphate deficiency)

Abnormalities of the platelet receptorsfor soluble agonistsThromboxane A2 receptor a mild bleeding disorder defective response tothe TxA2 analog U46619, albeit having a normal numberof TxA2 binding sites and normal equilibrium dissociation rate constants,the TxA2-induced IP3 formation, Ca2mobilization and GTPase activity were abnormal,. suggestingthat the abnormality in these platelets was impaired coupling between the TxA2 receptor, G protein,and PLC

Summary of platelet defects.