Kunishima et al. (2009) reported a Japanese boy who was incidentally found to have thrombocytopenia (40-60 x 10(9) platelets). Peripheral blood smears showed prominent giant platelets. Platelet aggregation function was normal, and bone marrow biopsy showed normal megakaryocyte ... Kunishima et al. (2009) reported a Japanese boy who was incidentally found to have thrombocytopenia (40-60 x 10(9) platelets). Peripheral blood smears showed prominent giant platelets. Platelet aggregation function was normal, and bone marrow biopsy showed normal megakaryocyte number and morphology. The mother of the patient also had macrothrombocytopenia. Cultured mature megakaryocytes from the proband showed large and irregular bleb protrusions, suggesting impaired megakaryocyte fragmentation and release of large platelets. Further studies indicated that the thrombocytopenia resulted from peripheral destruction, not platelet underproduction.
Freson et al. (2005) identified a heterozygous gln43-to-pro (Q43P) SNP in the TUBB1 gene in 8 (24.2%) of 33 unrelated individuals with macrothrombocytopenia. However, since inheritance in these 8 families was more consistent with autosomal recessive inheritance and ... Freson et al. (2005) identified a heterozygous gln43-to-pro (Q43P) SNP in the TUBB1 gene in 8 (24.2%) of 33 unrelated individuals with macrothrombocytopenia. However, since inheritance in these 8 families was more consistent with autosomal recessive inheritance and no other TUBB1 variants were identified, it was unclear how much this SNP contributed to the phenotype. The change, along with other factors, may predispose to development of macrothrombocytopenia. In a Japanese boy and his mother with macrothrombocytopenia, Kunishima et al. (2009) identified a heterozygous mutation in the TUBB1 gene (R318W; 612901.0001).