Imerslund-Grasbeck syndrome- a rare cause of megaloblastic anemia in an infant with homozygous mutation in CUBN gene: a case report and review of the literature
DOI:
https://doi.org/10.18203/2349-3291.ijcp20212487Keywords:
Megaloblastic anemia, Infant, B12 deficiency, Proteiuria, pancytopeniaAbstract
Megaloblastic anaemia is one of the important causes of pancytopenia in children and nutritional deficiencies of vitamin B12 and folate are the most common causes comprising 95% of these cases. Defects in absorption, transport and metabolism of vitamin B12 are well described, however, are very rare. We report a rare case of Imersland Grasbeck syndrome, in an infant who presented with pancytopenia, with defective absorption of B12-intrinsic factor complex at the ileum and defective tubular reabsorption of proteins in renal tubule due to same protein defect caused by mutations in two genes – CUBN (cubilin) and AMN (amnionless).
References
Pacitto A, Prontera P, Stangoni G. Imerslund-Gräsbeck Syndrome in an Infant with a Novel Intronic Variant in the AMN Gene: A Case Report. Int J Mol Sci. 2019;20(3):527.
Rodrigues, Vera & Dias, Alexandra & Brito, Maria & Galvão, Isabel & Cordeiro-Ferreira, Gonçalo. Severe MAin an infant. BMJ case reports. 2011;10.1136.
Filippo G, Rendina D, Rocco V, Esposito T, Gianfrancesco F, Strazzullo P. Imerslund-Gräsbeck syndrome in a 25-month-old Italian girl caused by a homozygous mutation in AMN. Ital J Pediatr. 2013;39:58.
Birn H, Fyfe JC, Jacobsen C, Mounier F, Verroust PJ, Orskov H, et al. Cubilin is an albumin binding protein important for renal tubular albumin reabsorption. J Clin Invest. 2000;105(10):1353-61.
Mackenzie IL, Donaldson RM Jr, Trier JS, Mathan VI. Ileal mucosa in familial selective vitamin B 12 malabsorption. N Engl J Med. 1972; 286(19):1021-5.
Grasbeck R, Gordin R, Kantero I, Kuhlback B. Selective vitamin B12 malabsorption and proteinuria in young people. A syndrome. Acta Med Scand. 1960;167:289-96.
Liang DC, Hsu HC, Huang FY, Wei KN. Imerslund-Gräsbeck syndrome in two brothers: renal biopsy and ultrastructural findings. Pediatr Hematol Oncol. 1991;8(4):361-5.
Ercan Z, Demir ME, Ulas T, Ingec M, Horoz M. A long-term follow-up of an Imerslund-Grasbeck syndrome patient with proteinuria. Nefrologia. 2013; 33(1):147-8.
