High diversity of chromosomal aberrations in a Brazilian myelodysplastic syndrome cohort
Myelodysplastic syndrome (MDS), an onco-hematological disease, is characterized by distinct levels of peripheral blood cytopenia, cell differentiation dysplasia and various types of chromosomal alterations. The Revised International Prognostic Scoring System uses the GTG-banding karyotype as one of the main components for scoring patient prognosis in MDS. Using GTG-banding karyotyping, we looked for chromosomal alterations in bone marrow samples obtained from a cohort of Brazilian patients in Goiás state, Brazil. Numerical and/or structural chromosomal alterations were detected in 15 of 29 patients. A total of 23 clones with the chromosomal alterations were obtained, of which 12 were numerical and 11 were structural. Complete trisomies were observed in five clones, complete monosomies in three clones, triploidies in three clones, and one clone contained a marker chromosome. Among the clones with structural alterations, two clones had a partial trisomy in 1q, five clones had partial monosomies, one clone contained an isochromosome, and three clones showed reciprocal translocations. The high diversity of chromosomal alterations is inherent to the strong degree of chromosomal and genomic instability in this myeloid disease. These alterations can be associated with the activation or inhibition of gene expression, leading to the deregulation of critical cell viability functions and hence ineffectiveness of hematopoiesis in MDS. Our study is the first to identify chromosomal alterations associated with this poorly studied disease in central Brazil.