Sebastian syndrome as a cause of thrombocytopenia

Sebastian syndrome is a rare disease associated with mutations in the MYH9 gene with an autosomal dominant pattern of inheritance whose phenotypic expression may vary in individuals with the same variant and even within the same family. It is clinically relevant due to the possibility of developing kidney failure, hearing loss and cataracts in youth or adulthood. We describe the case of Caucasian girl aged 9 years with identification of thrombocytopenia in the initial evaluation and a family history of Sebastian syndrome in whom genetic testing detected a mutation in the MYH9 gene. We highlight the importance of early diagnosis of hereditary thrombocytopenias, as well as the usefulness of the genetic study for these very rare diseases.