Inherited disorders of platelet function: selected updates

The gene variants responsible for the primary genotype of many platelet disorders have now been identified. Next-generation sequencing technology (NGST), mainly exome sequencing, has highlighted genes responsible for defects in platelet secretion (NBEAL2, gray platelet syndrome), procoagulant activity (STIM1, Stormorken syndrome), and activation pathways (RASGRP2, CalDAG-GEFI deficiency and integrin dysfunction; PRKACG, cyclic adenosine monophosphate-dependent protein kinase deficiency). Often disorders of platelet function are associated with a modified platelet production with changes in platelet number and size and can accompany malfunction of other organs or tissues. Most families have private mutations, and gene variants may prevent protein synthesis, abrogate function, or result in aberrant activated proteins. Nevertheless, bleeding severity is difficult to predict by genotype alone suggesting other factors. A major new challenge of NGST is to identify these factors and help improve patient care. This review concentrates on recent developments and is illustrated from personal observations.