ABSTRACT
Acute promyelocytic leukemia (APL) is characterized by the translocation t (15;17)(q22;q21) cytogenetic abnormality in the majority of cases. In most of the cases the cells of APL have normal, diploid karyotype. There are very few cases presented with very rare tetraploid karyotype with double translocation t(15;17)(q22;q12). We report the first case of tetraploid APL with double translocation t(15, 17) in Europe. A 66-year old male patient presented with dyspnea and unexplained dental bleeding. Blood work showed a white blood cell count of 1x109/L, hemoglobin was 124 g/ L, platelet count was 61x109/L and fibrinogen level was low (1.4 g/L). Cytogenetics showed a tetraploid karyotype. Fluorescence in situ hybridization analysis proved existence of clonal cells with translocation t (15,17) in 15% of metaphase nuclei and tetraploid subclonal cells with the same translocation in 70% of metaphase nuclei. Findings were consistent with APL, tetraploid variant and the patient started all-trans retinoic acid (ATRA) treatment. The patient achieved complete remission in 2 months and completed three consolidation therapy cycles with ATRA, idarubicin or mitraxontrate. Currently, the patient is undergoing maintenance therapy with ATRA, 6-mercaptopurine and weekly methotrexate.
ABSTRACT
Telomeres are specialized structures designed to protect the ends of linear chromosomes. They are dynamic structures such that in normal somatic cells they constantly shorten as cell division progresses. There is compelling evidence that telomere shortening leads to cell senescence, a process perceived as the main cause of aging in higher mammals. Therefore, the features of telomere shortening are of great importance in understanding cell senescence and aging in general. By identifying unique subtelomeric regions, large enough to produce strong chemiluminescent signals, we have provided a new tool for Southern blot analysis of individual human Xp/Yp telomeres. We extend these results with quantitative fluorescence in situ hybridization using peptide nucleic acid probe (PNA Q-FISH) analysis of telomeres on the Y chromosome. Our results demonstrates unequal shortening dynamics between the p and q telomeres.
