Inherited thrombocytopenias: from genes to therapy
Balduini, C.L.; Iolascon, A.; Savoia, A.
Haematologica 87(8): 860-880
2002
ISSN/ISBN: 0390-6078 PMID: 12161364 Document Number: 550932
Background and Objectives: Inherited thrombocytopenias are a heterogeneous group of rare diseases characterized by a reduced amount of blood platelets. Some are exclusive to megakaryocytes and platelets, while in others the pathology extends to other cell types. Although the defective genes, coding for membrane glyoproteins, cytoskeleton components and intracellular signaling pathways, as well as transcription factors, have been identified in most cases, the pathophysiology of these disorders is often unknown. This review focalizes recent contributions to clinical and diagnostic aspects, biology and treatments of familial thrombocytopenias. Evidence and Information Sources: The information presented here derives from literature and experience of the authors. The most relevant studies are critically analyzed and discussed. State of Art: The clinical and laboratory features of most of the inherited thrombocytopenias have been reviewed. The different forms have been classified into 3 groups depending on the platelet volume. Although this criterion is not completely satisfactory, it is one of the most useful in the diagnostic algorithms. We reported recent advances in Wiskott-Aldrich and Bernard-Soulier syndromes, as well as in MYH9-related diseases, a new nosological entity grouping old distinct forms known as May-Hegglin anomaly, Sebastian, Fetchner, and Epstein syndromes. Other, less frequent forms, are also discussed, including non-syndromic forms of mild thrombocytopenia that resulted to be genetically heterogeneous. Perspectives: In the past, inherited thrombocytopenias were considered exceedingly rare and the number of well-defined forms was very small. In the last few years, the widespread diffusion of electronic cell counters has allowed these conditions to be detected more frequently and several new entities have been identified by the coordinated efforts of physicians, biologists and geneticists. The pathogenesis of many new and old forms is being unraveled, thus providing insights on the molecular basis of platelet production and function. These knowledge will be a valuable resource for clinicians in the diagnostic approaches to these disorders.