Early recognition and treatment of TC II deficiency
Case report
Keywords:
transcobalamin II, vitamin B12, homocysteine, TCN 2 geneAbstract
Transcobalamin (TC) is a carrier protein and it delivers vitamin B12 to the cellular TC receptor. TC II deficiency is a very rare disease and is life-threatening if left untreated. It is an Autosomal recessive disease and needs lifelong treatment. The clinical presentations are variable, started at early infancy, and sometimes mimic severe combined immunodeficiency or acute leukemia. It includes failure to thrive, diarrhea, anemia and or pancytopenia, hypotonia, developmental delay, and recurrent infection. Diagnosis of TC II deficiency is suspected based on clinical presentations with megaloblastic anemia, the elevation of plasma homocysteine, and urine methylmalonic acid level with a normal level of vitamin B12 and folate. Molecular analysis of the TCN 2 gene is needed for confirmation of the diagnosis. We present a case of 2 years old Saudi boy who was admitted to the hospital with a history of fever, recurrent chest infection, failure to thrive with diarrhea, and hypotonia, and his complete blood counts showed Pancytopenia. Though, normal vitamin B12 level and folate level, homocysteine, and urine methylmalonic acid lever were elevated. Peripheral smear and bone marrow aspiration and biopsy revealed Hypersegmented neutrophils and megaloblastic change.
Downloads
References
Arlet, JB, Varet, B, Besson, C. Favorable long-term outcome of a patient with transcobalamin II deficiency. Ann Intern Med 2002;137:704–5
C.M. Pfeiffer, ... K.L. Caldwell, in Encyclopedia of Human Nutrition (Third Edition), 2013 Biochemical Indices
Kaikov Y, Wadsworth L, Hall C, Rogers P. Transcobalamin II: case report and review of the literature. Eur J Pediatr 1991; 150:841±3
Li N, Rosenblatt DS, Seetharam B (1994b) Nonsense mutations in human transcobalamin II deficiency. Biochem Biophys Res Comm 204:1111–1118
Namour F, Helfer AC, Quadros EVet al (2003) Transcobalamin deficiency due to an intra exonic cryptic splice set activation. Br J Haematol 123:915–920
- Philip Lanzkowsky, in Lanzkowsky's Manual of Pediatric Hematology and Oncology (Sixth Edition), 2016), Transcobalamin II Deficiency (OMIM 275350)
Robert M. Kliegman MD, in Nelson Textbook of Pediatrics, 2020
Isolated Methylmalonic Acidemias Defects in Metabolism of Amino Acids
Selma Ünal, Feryal Karahan, Tuğba Arıkoğlu, Asuman,Akar,Semanur Kuyucu.(2018): Different Presentations of Patients with Transcobalamin II Deficiency: A Single-Center Experience from Turkey Transkobalamin II Eksikliği Olan Hastaların Farklı Sunumları: Türkiye’den Tek Merkez
Servicio de Neonatologia, Hospital Clínico de San Carlos, Madrid; b Hematología, Hospital Clínico de San Carlos, Madrid, Spain; c Academic Department of Haematology, Royal Free Hospital and School of Medicine, London, U K
Watkins D, Rosenblatt DS (2011) Inherited disorders of folate and cobal-amin transport and metabolism, In: Valle D, Beaudet AL, Vogelstein, B, Kinzler KW, Antonarakis SE, Ballabio A, eds. The Online Metabolic and Molecular Bases of Inherited Disease, 8th and. Chap 155, online, McGraw-Hill, New-York
Yildirim, ZK, Nexo, E, Rupar, T, Büyükavci, M. Seven patients with transcobalamin deficiency diagnosed between 2010 and 2014: a single-center experience. J Pediatr Hematol Oncol 2017;39:38–41
Y. J. Trakadis • A. Alfares • O. A. Bodamer • M. Buyukavci • J. Christodoulou •P. Connor • E. Glamuzina • F. Gonzalez-Fernandez • H. Bibi • B. Echenne • I. Manoli •J. Mitchell • M. Nordwall • C. Prasad • F. Scaglia • M. Schiff • B. Schrewe • G. Touati •M. C. Tchan • B. Varet • C. P. Venditti • D. Zafeiriou • C. A. Rupar • D. S. Rosenblatt •D. Watkins • N.Braverman:(2013) Update on transcobalamin deficiency: clinical presentation, treatment and outcome DOI 10.1007/s10545-013-9664-5,
Published
How to Cite
Issue
Section
Copyright (c) 2022 International journal of health sciences
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Articles published in the International Journal of Health Sciences (IJHS) are available under Creative Commons Attribution Non-Commercial No Derivatives Licence (CC BY-NC-ND 4.0). Authors retain copyright in their work and grant IJHS right of first publication under CC BY-NC-ND 4.0. Users have the right to read, download, copy, distribute, print, search, or link to the full texts of articles in this journal, and to use them for any other lawful purpose.
Articles published in IJHS can be copied, communicated and shared in their published form for non-commercial purposes provided full attribution is given to the author and the journal. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.
This copyright notice applies to articles published in IJHS volumes 4 onwards. Please read about the copyright notices for previous volumes under Journal History.
