Cytogenetic and Cytochemical Studies on Marrow Cells in B12 and Folate Deficiency

T lIE MORPHOLOGIC ABNORMALITIES of red and white cell pre-cursors in vitamin B12 and folate deficiency have been known in detail for mnanv years, as have the morphologic changes by which a megaloblastic mar-row becomes transformed to a normoblastic one when appropriate substitution therapy is given. By contrast, little information has until recently been avail-able on the functional derangement accompanying the structural abnormalities in these cells, or on the way in which such malfunction leads to underproduc-tion of red cells, leukocytes, and platelets. Since the introduction of new technics, reports have begun to appear on the chromosome constitutio&’7’5”9 and DNA synthesizing activity of megaloblasts.’7’24 In the present paper we report attempts to clarify the functional defect by means of the combination of chromosome studies, autoradiography, and DNA measurements in individual cells. These first results suggest that it may be possible to explain the defect in terms of a deranged DNA metabolism. Further combined studies of this nature may well produce a model for comparison with other pathologic cell