Apoptosis and platelet biogenesis: A new piece of information on a debated topic

Thrombocytopenia 4 (THC4) is an extremely rare form of inherited thrombocytopenia caused by mutations in the gene encoding cytochrome c (CYCS). The mechanism leading to reduced blood platelets remains unclear, although an unrestrained megakaryocyte apoptosis as a consequence of CYCS alterations has been proposed. The report of a TCH4 family with a novel CYCS variant unravels clues on the pathogenesis of this disorder and spotlights back on the still-discussed role of apoptosis in human platelet and megakaryocyte physiology. Commentary on: Štika et al. A novel thrombocytopenia-4-causing CYCS gene variant decreases caspase activity: Three-generation study. Br J Haematol 2024; 205: 2450-2458.