Nucleic Acid Composition of Bone Marrow Mononuclear Cells in Cobalamin Deficiency

Recent studies using anion exclusion chromatography have suggested that uracil is misincorporated into the DNA of patients with megaloblastic anemia to levels detectable by nonradioactive methods. We have investigated the nucleo-tide composition of DNA from the bone marrow mononu-clear cells of eight patients with cobalamin deficiency and compared this with that found in normal subjects. The me-dian level of uracil in the megaloblastic group was 0.082 mol % of cytosine (approx. 0.02 mol % of all bases in DNA), which was similar to that found in the control group (median 0.085 mol % of cytosine) and may be attributable, at least in ENTRAL TO MOST theories on the pathophysiology C of megaloblastic hemopoiesis is that a deficiency of folate, either absolute or functional (associated with cobala-min deficiency), leads to impairment of purine synthesis and reduced methylation of deoxyuridine monophosphat