Major problems in this regard have been reported previously with the Sysmex XE-2100 and the Beckman Coulter LH750 (Noris et al, 2009; Latger-Cannard et al, 2012), and similar limitations have been observed in the present study with the Sysmex XE-2100 used in Centre 4 and with the impedentiometric channel of the Abbott Cell-Dyn 3700 instrument used in Centre 3: both counters did not measure MPV in several patients with MYH9-RD, ITs of unknown origin or ITP because of their inability to recognize very large platelets. The gene discussed is MYH9; the disease is autoimmune thrombocytopenic purpura.