Detection of trisomy 8 using conventional cytogenetic techniques and interphase FISH analysis in 34 myeloid disorders: A comparative study

Trisomy for chromosome 8 is one of the most common chromosome abnormalities detected in myeloid disorders. However, and despite its great incidence, its biologic significance remains poorly understood. Recently, some reports have shown the existence of masked trisomy 8 in myeloid disorders. To try to detect occult trisomy 8, we performed a study in which 34 myeloid disorders with apparent normal karyotypes using conventional cytogenetic techniques were analyzed using fluorescence in situ hybridization (FISH) analysis. Masked trisomy 8 was not detected in any of the 34 cases studied. This suggests that trisomy 8 may be a rare event in myeloid disorders in which an optimal conventional cytogenetic analysis has been performed. The acquisition of trisomy 8 either in early neoplastic stages in some cases or in late neoplastic stages in others and the absence of masked trisomy 8 suggest that this chromosome alteration may not be essential to the development of myeloid disorders.