Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Campus Gasthuisberg, O&N1, Herestraat 49, Box 911, 3000 Leuven, Belgium
Megakaryopoiesis is a differentiation process in the bone marrow that ends with platelet formation starting from pluripotent hematopoietic stem cells. This process is strictly regulated by lineage-specific transcription factors and the cytokine thrombopoietin to guarantee daily renewal of a well-defined number of platelets with a normal function. Platelets are essential as they control primary hemostasis via adhesion, activation and clot formation at the site of injury. Defects in megakaryopoiesis can lead to thrombocytopenia with or without an associated functional platelet defect. Thrombocytopenia is often associated with spontaneous or trauma-induced mucocutaneous bleeding problems. In this review, we briefly discuss different types of inherited thrombocytopenias that are grouped according to the defective underlying molecular pathway such as a defect in the regulation of transcription, the TPO pathway, cytoskeletal proteins, apoptosis, and some others regulators for which the exact role in megakaryopoiesis or platelet formation is not yet clear.