Volumen: 14 # Number : 3
Publication Date : Septiembre - Diciembre Year: 2010
Authors: Carolina B. Belli, Silvia Benasayag, María I. Gallino, Walter A. Correa, Irene B. Larripa
Abstract: Cytogenetic studies and molecular mechanisms in Myelodysplastic Syndromes
Genetic alterations due to mutations, balanced or unbalanced chromosomal rearrangements, acquired uniparental disomy, haploinsufficiency and epigenetic findings are related to the development and progression of MDS. Among others, NRAS, FLT3, TP53, RUNX1, p15INK4b, TET2, ASXL1 y RPS14 are frequently altered in MDS.
Approximately, 30-59% of patients with de novo MDS shows abnormal karyotypes and these percentages are increased in more advanced subtypes according to FAB and WHO classifications. The most frequently aberrations are: -5/del(5q) [2%-11%], -7/del(7q) [2%-5%], +8 [3%-12%], del(20q) [2%-4%], –Y [2%-4%] and complex karyotypes (≥3 alterations) [10-20%].
Around 60-90% of secondary MDS exhibits altered cytogenetic results with an increase of translocations and complex karytypes [50%]. Abnormalities in chromosomes 5 and 7 [80%] have been associated with exposition to alkylating agents and 11q23 or 21q22 with topoisomerase II inhibitors.
Karyotype has become an important tool for diagnosis, prognosis, treatment and monitoring of MDS patients. Cytogenetic categories of risk according to IPSS have been recognized using either FAB or WHO classifications and afterward adopted by the WPSS system. Although the Intermediate group is heterogeneous, the International Working Group on MDS Cytogenetics suggests continuing with its use until a new multicentric study will be performed.
Key words: Cytogenetics; Myelodysplastic Syndromes; Genes, Prognosis.
Pages : 91-102
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