[Clonal study of hematopoietic cells]

Clonal analyses using X-chromosome inactivation patterns of the phosphoglycerate kinase (PGK) and DXS255 (M27 beta) genes were performed in women with various hematological diseases or normal hematopoiesis. Four (17%) of 24 hematologically normal females had a skewed Lyonization pattern. It, however, appeared that in the majority of cases clonality determination of myeloid cells would be possible in comparison with lymphocytes. Blasts of acute myeloid leukemia (AML) (21) and granulocytes and bone marrow cells of chronic myeloproliferative disorders (6) were all shown to be clonal, suggesting that this method was useful for the concept formation of a clonal disorder. Twelve of 14 patients with the myelodysplastic syndromes had a clonal pattern and 8 of 10 patients with aplastic anemia had a polyclonal pattern. Three of 34 patients with AML during remission were diagnosed as a clonal hematopoiesis and associated with features of myelodysplasia during remission, when clonal patterns are different in patients with the same disease, it seems important to elucidate their clinical implications.