CASE REPORT article
Front. Pediatr.
Sec. Pediatric Hematology and Hematological Malignancies
Volume 13 - 2025 | doi: 10.3389/fped.2025.1645600
Vitamin B12 Deficiency in a Young Male with Imerslund-Gräsbeck Syndrome: Case Report
Provisionally accepted
- Second Hospital of Hebei Medical University, Shijiazhuang, China
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Imerslund-Grä sbeck syndrome (IGS) is a rare genetic disorder characterized by selective vitamin B12 deficiency co-existing with asymptomatic proteinuria. It is caused by bi-allelic mutations in either the CUBN or AMN gene, which encode the two protein components of the cobalamin-intrinsic factor receptor. Patients stay healthy with lifelong parenteral administration of vitamin B12. Here, we report a case of a young male who presented with severe macrocytic anemia and asymptomatic proteinuria from the age of one year. His low serum level of vitamin B12 suggested vitamin B12 deficiency. Further, the patient was heterozygous for the AMN variant c.1006+34_1007-31 del mutation with duplication of exons 2-3, indicating a definite diagnosis of typical IGS. He was treated by administration of vitamin B12 injections, resulting in rapid improvement of hemoglobin levels. However, the previously detected proteinuria was found to persist at follow-up.
Keywords: vitamin B12 deficiency, Imerslund-Gräsbeck syndrome, AMN gene, Megaloblastic anemia, Proteinuria
Received: 25 Jun 2025; Accepted: 14 Aug 2025.
Copyright: © 2025 Xing, Guo, Li, Zhou, Lin and Wang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Yan Wang, Second Hospital of Hebei Medical University, Shijiazhuang, China
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