RESUMEN
Introduction and importance: Hereditary Folate Malabsorption (HFM) is an extremely rare autosomal recessive disorder with in the existence of only 30 families world-wide. It presents with hematological, gastrointestinal, and neurological problems. Case presentation: Three-month-old-boy with a familial history of HFM presented to the clinic due to persistent fatigue, yellowish discoloration, feeding refusal, and pancytopenia. The patient received 3 packs of Red Blood Cells (RBCs). Five days after received 3 packs of RBCs, the patient presented with a fever of 38.3 Celsius with pancytopenia. The patient had low level of all immunoglobulins. He was started on broad-spectrum antibiotics. Testing for the HFM's SLC46A1 gene mutation, was positive. The patient was started on Leucovorin and Respirm. Clinical discussion: In this case, HFM presented as a neutropenic fever, hypoimmunoglobulinemia, low serum folate, elevated homocysteine, and a positive mutation on the SLC46A1. HFM has a wide-spectrum of presentations which includes hematological, neurological, immunological and gastrointestinal. Treatment involves the administration of folinic acid in either oral or intramuscular injections. Conclusion: HFM can present as neutropenic fever. High index of suspension is to be maintained when the presenting symptoms of the patients vary over a large number of systems. Genetic counseling is needed for parents when both are carrying an autosomal recessive allele.