Molecular genetic approach to the analysis of clonal proliferation in hematologic disorders.

The clonal composition of each cell population was determined from the characteristic methylation pattern of DNA and the restriction fragment length polymorphism (RFLP) of the hypoxanthine phosphoribosyltransferase (HPRT) and phosphoglycerate kinase (PGK) genes, both located on the X chromosome. About 71% of Japanese females are heterozygous in terms of the RFLP of either HPRT or PGK genes, which was demonstrated by using 5' genomic DNA or cDNA probes for these genes. All 3 cases of chronic myeloproliferative disorders showed monoclonal patterns. AML or ALL cases demonstrated either monoclonal or polyclonal patterns depending upon the percentage of blastic cells. Monoclonal patterns were seen in 3 of 4 cases of myelodysplastic syndromes and both PNH cases.