It is now well established that a group of autosomal dominant inherited thrombocytopenias with large/giant platelets and leukocyte inclusions, initially designed as May Hegglin Anomaly (MHA: MIM 155100), Sebastian, Fechtner or Epstein Syndrome (SBS: MIM 605249, FTNS: MIM 153640, or EPTS: MIM 153650, respectively) are in fact a clinical continuum associated with mutations in the MYH9 gene. This evidence concerns the gene MYH9 and macrothrombocytopenia and granulocyte inclusions with or without nephritis or sensorineural hearing loss.