Clonal studies in the myelodysplastic syndrome using X-linked restriction
fragment length polymorphisms
A Tefferi, SN Thibodeau and LA Solberg
Division of Hematology and Internal Medicine, Mayo Clinic, Rochester, MN
55905.
We used the X-linked restriction fragment length polymorphism (RFLP)-
methylation strategy to study the clonal basis of the myelodysplastic
syndrome (MDS) in seven patients. RFLP-methylation analysis was performed
on cell populations from bone marrow (BM) aspirates and peripheral blood
using probes specific for the hypoxanthine phosphoribosyltransferase (HPRT)
or phosphoglycerate kinase (PGK) gene regions. Density gradient
centrifugation methods were used to separate granulocytes and monocytes,
and T lymphocytes were positively selected by CD2 (a pan-T marker)
immunoconjugated magnetic beads. Cell populations from BM aspirates in 6 of
the 7 patients with MDS showed a monoclonal pattern of X-inactivation. The
neutrophilic and T- lymphocytic cell fractions were analyzed in 4 of the 6
patients, and the monocytic cell fraction in one of these, and all
fractions analyzed showed a similar monoclonal pattern. In 2 of the latter
4 patients, both of whom had normal karyotypes, DNA from a skin biopsy
showed a polyclonal pattern. Our data suggest that MDS is a clonal
disorder, even in the absence of detectable cytogenetic abnormalities, and
that the abnormal clone is capable of myeloid, monocytic, and lymphoid
differentiation.
Volume 75,
Issue 9,
pp. 1770-1773,
05/01/1990
Copyright © 1990 by The American Society of Hematology
