The crucial roles of GFI1B in platelet development

The identification of eight new Growth Factor Independence 1B (GFI1B) variants in families with bleeding and platelet disorders may result in the identification of therapeutic targets for these bleeding disorders. Half of the patients had thrombocytopaenia. Several patients showed similar platelet abnormalities as the earlier reported patients with the GFI1B defect, such as decreased α-granule numbers and/or platelet CD34 expression. The GFI1B protein is known to regulate gene expression. Almost all GFI1B variants were still active, while one had lost this function in transcription repression assays. If the new GFI1B variants are disease-causing, this would indicate a distinct molecular mechanism that contributes to defective platelet production and α-granule formation, resulting in bleeding complications.