Evidence for pluripotent stem cell origin of idiopathic myelofibrosis: clonal analysis of a case characterized by a N-ras gene mutation.

Three cases of idiopathic myelofibrosis were screened for the presence of mutations at codon 12, 13, or 61 of the ras gene family by a rapid method based on polymerase chain reaction and hybridization to mutation-specific oligonucleotides. PB cells of one patient showed a point mutation at codon 12 of the N-ras oncogene. This molecular genetic hallmark was used to investigate the clonal relationship of different cell lineages by cell separation analysis. Presence of the N-ras 12 mutation in granulocytes, monocytes, B cells, and T lymphocytes, as well as erythroblasts, indicates that idiopathic myelofibrosis originates from a pluripotent stem cell, at least in this patient.