Imerslund-Gräsbeck syndrome presenting with a 12-year history of intermittent proteinuria and anemia: a case from the Middle East.

backgroundImerslund-Gräsbeck Syndrome (IGS) is a rare autosomal recessive disorder characterized by selective cobalamin (vitamin B12) malabsorption and often accompanied by proteinuria. Mutations in CUBN or AMN genes underlie the condition, which usually manifests in childhood with megaloblastic anemia, failure to thrive, or recurrent infections. CASE PRESENTATION: We report a 15-year-old Iranian boy with a 12-year history of recurrent anemia and intermittent proteinuria. He presented with fatigue, nausea, and anorexia. Laboratory evaluation showed pancytopenia, macrocytic anemia (Hb 7.5 g/dL → 6.9 g/dL), thrombocytopenia (91 × 10³/µL → 38 × 10³/µL), and a severely reduced serum vitamin B12 level (74.4 pg/mL). Liver enzymes were elevated (AST 346 U/L, ALT 225 U/L), while renal function was preserved. Bone marrow aspiration confirmed megaloblastic changes. Despite the lack of confirmatory genetic testing, the diagnosis of IGS was made based on clinical findings and hematologic response. Treatment with intramuscular hydroxocobalamin (1000 mcg/day) and folic acid resulted in marked improvement, with hemoglobin rising to 11.4 g/dL and normalization of blood counts within three weeks. Intermittent proteinuria persisted.

conclusionThis case emphasizes the importance of considering IGS in children and adolescents with unexplained macrocytic anemia and proteinuria, particularly in the Middle East where the condition is underdiagnosed. Early recognition and lifelong vitamin B12 supplementation are critical to prevent irreversible complications such as neurological deficits, developmental delay, and growth impairment.