Congenital Isolated Folic Acid Malabsorption: Case Report

We report the case of a female child with congenital isolated malabsorption of folic acid. The patient was referred to our hospital for pancytopenia and a tendency to various infections, but with no neurological disturbances. A bone marrow aspiration demonstrated megalobastic anemia and serum folic acid was low. An immunodeficiency test was therefore performed, which revealed impairment of both cellular and humoral immunity. The defect persisted after considerable doses of folate were administered orally to the patient. However, parenteral administration of folic acid removed pancytopenia, and restored normal levels of T CD8+, NK, B and immunoglobulins. Our patient, responded only to parenteral folate and her immunologic recovery after parenteral folate repletion was dramatic and provides strong in vivo evidence of the importance of folates for lymphocyte function in humans. Our patient’s history shows that while it is easy to reverse the systemic consequences of folate deficiency, patients must not stop taking their folate supplementation because they believe that their disorder disappeared.