Transient 7q- in association with megaloblastic anemia due to dietary folate and vitamin B12 deficiency.

Purpose : We describe a case of acquired megaloblastic anemia in a 7 1/2-year-old white boy whose bone marrow showed unusual morphology and a nonrandom del(7q). Methods and Results : This patient was found to have megaloblastic anemia due to acquired folic acid and vitamin B 12 deficiencies. Bone marrow examination exhibited unusual morphology, including intranuclear inclusions. Cytogenetic analysis revealed a nonrandom del(7q), a clonal abnormality usually associated with the myelodysplastic syndrome (MDS) or secondary acute myelogenous leukemia (AML). Specific treatment with both folic acid and vitamin B 12 corrected the clinical as well as the marrow morphologic and cytogenetic abnormalities. Conclusions : Megaloblastic anemia causes abnormalities in DNA synthesis and repair that may result in unusual marrow findings, both morphologic and cytogenetic. Such findings must be interpreted with caution in view of total reversibility with specific vitamin therapy.