[Isochromosome 17q as the sole alteration in 2 patients with a myelodysplastic syndrome and its relation to myeloperoxidase activity].

Two patients diagnosed of myelodysplastic syndrome with an isochromosome i (17q) as the only chromosomal alteration are presented. The MAC method (i.e., morphology, antibodies, chromosomes) was applied in the study of one of the patients, it being found that all the myeloperoxidase-positive cells carried the i (17q) anomaly. Such finding might suggest that those patients with i (17q) as the only chromosomal alteration could have specific clinical and cytological features.