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Myelodysplastic syndromes (mds) are a group of clonal haematopoietic stem cell diseases characterised by cytopaenia, dysplasia in one or more of the major myeloid cell lines, ineffective haematopoiesis and an increased risk of developing acute myeloid leukaemia (AML).1 Cytogenetic and molecular abnormalities are key elements in the diagnosis of MDS. Clonal chromosomal abnormalities in MDS have been observed in 30–80% of patients, depending on the subtype and whether it is de novo or mutagen-induced. 2,3 For the other 20–70% of MDS patients with normal karyotypes, there is substantial evidence for the presence of submicroscopic alterations—such as point mutations, microdeletions, microamplifications, epigenetic changes or copy number neutral loss of information—which may form the genetic basis of the disease.4–6 The percentage of clonal abnormalities in the literature varies between 23–78%.7–9
Over time, MDS has been increasingly recognised as a cause of bone marrow failure; however, the precise incidence of de novo MDS is unknown.10 Jacobs et al. have suggested that the distribution of specific chromosomal aberrations in MDS varies between Western and Asian countries.11 Another report also indicated geographical and ethnic differences in the frequency of specific chromosomal aberrations.12 The incidence of chromosomal abnormalities in Indian population has been reported to vary from 37.5–88%.13 In addition, the frequency of chromosomal abnormalities varies between 37–50% in China, Thailand, Hong Kong and Japan.13,14 Complex aberrations have been more frequently observed in Indian patients as compared to those from other Asian countries.13
As such, ethnic and/or geographical differences could be heterogeneous and contribute to clinical, cytogenetic or molecular events leading to MDS. Available reports on the incidence of MDS mostly originate from European countries, although major studies have been conducted in Japan.15–22 To the best of the authors’ knowledge, this is the first report detailing the cytogenetic profile of Omani patients with MDS. In order to analyse ethno-geographical differences in the pathogenesis of MDS, the current article aimed to compare the cytogenetic findings of Omani patients with de novo MDS with available data from Europe, North and South America, Africa and other Asian countries.
Methods
Data were collected from all patients with MDS presenting between 2006–2013 to the Department of Haematology at the Sultan Qaboos University Hospital (SQUH), a tertiary...