Myeloproliferative disorders: usefulness of X-linked probes in diagnosis

Myeloproliferative disorders are neoplasms of the pluripotent hematopoietic stem cell. Accurate diagnosis and distinction from reactive processes can be difficult therein with cytogenetic analysis only being useful in a minority of patients. Use of X-linked restriction fragment length polymorphism and methylation analysis has enabled clonal analysis to be performed in up to 50% of females, significantly increasing the proportion of analyzable patients over methods dependent on glucose-6-phosphate dehydrogenase heterozygosity. Using hypoxanthine phosphoribosyl transferase and phosphoglycerate kinase probes, we have demonstrated monoclonality of peripheral blood leukocytes in three females with myeloproliferative disorders who had uninformative chromosomal analysis. This technique greatly enhances the diagnosis of early myeloproliferative disorder.