Chromosome 7 monosomy and deletions in myeloproliferative diseases

We studied deletion and monosomy of chromosome 7 in 150 patients with myelo proliferative diseases. We found 8/150 patients with monosomy 7 by cytogene tics and 4/150 with deletions of the long arm of chromosome 7 by restrictio n fragment length polymorphism (RFLP) analysis performed with Southern and polymerase chain reaction. To overcome limitation of RFLP analysis, we rest ricted loss of heterozygosity study with microsatellites to 45 patients, ob serving deletion 7q31.1 in 7/45 patients. In all patients with molecular al terations the deletion was observed only in myeloid cells, while the monoso my was detected in both myeloid precursor and lymphocytes. This finding sug gests a CD34-totipotent stem cell origin for the monosomy and a colony form ing unit - granulocyte, erytrocyte, monocyte, megakaryocytes (CFU-GEMM) ste m cell origin for the deletions. (C) 2001 Elsevier Science Ltd. All rights reserved.