Report of a young girl with MYH9 mutation and review of the literature. 
MYH9 mutations cause the inherited macro-thrombocytopenic syndromes of May-Hegglin anomaly, Fechtner syndrome, Sebastian syndrome, and Epstein syndrome, collectively referred to as MYH9-related disease.  We present the case of a girl with MYH9-related disease whose diagnosis was facilitated by platelet electron microscopy and MYH9 sequencing.  We discuss our patient's clinical presentation, now with 12 years of follow-up.  We also discuss management and her possible prognosis given her specific MYH9 mutation.