Morales Camacho, Rosario MaríaSánchez, JavierMarcos Luque, IreneBernal, RicardoFalantes, José F.Pérez Simón, José Antonio2022-02-102022-02-102014Morales Camacho, R.M., Sánchez, J., Marcos Luque, I., Bernal, R., Falantes, J.F. y Pérez Simón, J.A. (2014). An Active Isodicentric X Chromosome in a Case of Refractory Anaemia with Ring Sideroblasts Associated with Marked Thrombocytosis. Case Reports in Genetics, 1-3.2090-6544https://hdl.handle.net/11441/129831Refractory anaemia with ring sideroblasts and marked thrombocytosis (RARS-T) is a provisional entity in the World Health Organization (WHO) classification. It displays features characteristic of both myelodysplastic syndrome and myeloproliferative neoplasia plus ring sideroblasts ≥15% and marked thrombocytosis. Most patients with RARS-T show a normal karyotype. We report a 76-year-old woman diagnosed with RARS-T (76% of ring sideroblasts) with JAK2 (V617F) mutation and a load of 30-40%. Classical and molecular cytogenetic (FISH) studies of a bone marrow sample revealed the presence of isodicentric X chromosome [(idic(X)(q13)]. Moreover, HUMARA assay showed the idic(X)(q13) as the active X chromosome. This finding was correlated with the cytochemical finding of ring sideroblasts. To our knowledge, this is the first reported case of an active isodicentric X in a woman with RARS-T.application/pdf3engAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Refractory anaemiaRing sideroblastsMarked thrombocytosis (RARS-T)World Health Organization (WHO) classificationMyelodysplastic syndromeMyeloproliferative neoplasiaHUMARA assayWomenJAK2 (V617F) mutationinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccesshttps://doi.org/10.1155/2014/205318