Platelet CD34 expression and α/δ-granule abnormalities in GFI1B - and RUNX1 -related familial bleeding disorders

To the editor: Mutations in the transcription factor Growth Factor Independent 1B ( GFI1B ) are causal to an autosomal dominant inherited bleeding disorder characterized by macrothrombocytopenia and reduced platelet α-granule numbers (platelet-type bleeding disorder-17, Online Mendelian