Trisomies 8 and 9 not detected with fish in patients with mastocytosis.

Mastocytosis is a rare disease characterized by proliferation of mast cells in one or several organs. With conventional cytogenetics about 35% of the patients have chromosomally abnormal clones in bone marrow cells. It has been proposed to include the mast cell disease among the myeloproliferative disorders, in which trisomy for chromosome 8 and 9 can appear in the bone marrow cells. In this study bone marrow cells from eight patients with mastocytosis, two had as well an associated hematological disease, have been examined with fluorescence in situ hybridization (FISH) for enumeration of chromosome no8 and 9. In conventional cytogenetics two patients had clones with del(20) and 47,XY,+14/45, X,-Y, respectively. None of the patients with mastocytosis had clones with trisomy 8 or 9 with either cytogenetics or FISH.