Association of loss of heterozygosity with cytogenetic abnormalities in acute myeloid leukemia and myelodysplastic syndrome

Association of loss of heterozygosity with cytogenetic abnormalities in acute myeloid leukemia and myelodysplastic syndrome

Author Pinheiro, Ronald Feitosa Autor UNIFESP Google Scholar
Serio, Francine Menotti Autor UNIFESP Google Scholar
Silva, Maria Regina Regis da Autor UNIFESP Google Scholar
Briones, Marcelo Ribeiro da Silva Autor UNIFESP Google Scholar
Chauffaille, Maria de Lourdes Lopes Ferrari Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract Deletions on chromosomes 5 and 7 are frequently seen in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). It is assumed that these deletions indicate loss of tumor suppressor genes on these chromosomes and until these tumor suppressor genes are identified, the functional consequences of these deletions and the molecular basis of these myeloid disorders cannot be completely understood. We evaluated loss of heterozygosity (LOH) in 44 patients (18 MDS and 26 AML, diagnosed according to WHO classification criteria) at diagnosis, using a four-microsatellite marker panel: an intragenic marker on the 7th intron of gene IRF-1 of the 5q31.1 region and three markers located inside the 7q31.1 region and correlated the LOH with karyotype abnormalities. The microsatellites chosen corresponded to chromosome regions frequently deleted in MDS/AML. The samples with Q (peak area) less than or equal to 0.50 were indicative of LOH. The percent of informative samples (i.e., heterozygous) for the intragenic microsatellite in gene IRF-1 and in loci D7S486, D7S515 and D7S522 were 66.6, 73.7, 75.5, and 48.8%, respectively. Cytogenetic abnormalities by G-banding were found in 36% (16/44) of the patients (2 of 18 MDS and 14 of 26 AML patients). We found a significantly positive association of the occurrence of LOH with abnormal karyotype (P < 0.05; chi-square test) and there were cases with LOH but the karyotype was normal (by G-banding). These data indicate that LOH in different microsatellite markers is possibly an event previous to chromosomal abnormalities in these myeloid neoplasias.
Keywords Myelodysplastic syndrome
Acute myeloid leukemia
Cytogenetic abnormalities
Loss of heterozygosity
Language English
Sponsor Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Date 2008-07-01
Published in Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 41, n. 7, p. 610-614, 2008.
ISSN 0100-879X (Sherpa/Romeo)
Publisher Associação Brasileira de Divulgação Científica
Extent 610-614
Origin http://dx.doi.org/10.1590/S0100-879X2008000700010
Access rights Open access Open Access
Type Article
SciELO ID S0100-879X2008000700010 (statistics in SciELO)
URI http://repositorio.unifesp.br/handle/11600/4474

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