Beta1-tubulin gene mutation platelets are not macrothrombocytes.

摘要

The brief report by Kunishima et al describing a mutation of the beta1 tubulin gene affecting microtubule assembly is of interest, but data presented do not support association of the genetic defect with macro-thrombocytopenia. The authors stated both the male propositus and his mother had prominent appearance of giant platelets on peripheral blood smears, and provided light (Figure 1A) and electron micrographs (Figure 1B) to support that finding. The patient platelet in Figure 1 A has damaged peripheral cytoplasm that may make it appear larger than a normal cell, but, more important, the platelet is significantly smaller than any red blood cell in the same field. No discoid platelets from the control or patient are present in the electron micrographs (Figure 1B). As a result, it is difficult to be certain there is any real size difference between patient and control platelets. Surely the authors must be aware that giant platelets from all of the known macrothrombocytopenias are larger than red blood cells, and many exceed the size of lymphocytes, monocytes, and neutrophils. It might have been helpful if the authors had provided the mean platelet volumes of the mother and child.