An active isodicentric x chromosome in a case of refractory anaemia with ring sideroblasts associated with marked thrombocytosis

Rosario M Morales Camacho; Javier Sanchez; Irene Marcos Luque; Ricardo Bernal; Jose F Falantes; Jose A Pérez-Simón

doi:10.1155/2014/205318

An active isodicentric x chromosome in a case of refractory anaemia with ring sideroblasts associated with marked thrombocytosis

Case Rep Genet. 2014:2014:205318. doi: 10.1155/2014/205318. Epub 2014 Jan 30.

Authors

Rosario M Morales Camacho¹, Javier Sanchez², Irene Marcos Luque³, Ricardo Bernal¹, Jose F Falantes¹, Jose A Pérez-Simón¹

Affiliations

¹ Department of Haematology, Institute of Biomedicine of Seville (IBIS), University Hospital Virgen del Rocío, CSIC, University of Seville, 41013 Seville, Spain.
² Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville (IBIS), University Hospital Virgen del Rocío, CSIC, University of Seville, 41013 Seville, Spain.
³ Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville (IBIS), University Hospital Virgen del Rocío, CSIC, University of Seville, 41013 Seville, Spain ; Centre of Biomedical Network Research on Rare Diseases (CIBERER), 41013 Seville, Spain.

Abstract

Refractory 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.