Abstract

Methylcobalamin deficiency type CblE is a rare autosomal recessive inborn error of intracellular cobalamin metabolism. The clinical presentation is characterized by megaloblastic anemia, delayed psychomotor development, hypotonia, seizures, nystagmus, impaired visual acuity, and failure to thrive. The symptoms onset is usually within the 3rd year of life, with most children presenting within the first. The biochemical markers of CblE deficiency are hyperhomocysteinemia, homocystinuria and hypomethioninemia. We report a case of late onset (11 yo) methylcobalamin deficiency type CblE presenting with isolated macrocytic anemia and no neurological impairment. Genetic analysis of the MTRR gene allowed to identify two compound heterozygous variants, c.626C>G; [p.(Ser209*)] and c.1715C>T [p.(Pro572Leu)], which were never reported in the literature before. The therapy with hydroxocobalamin was effective on the patient anemia and allowed to reach control of the clinical picture. The aim of this article is to show that isolated macrocytic anemia and hyperhomocysteinemia may be caused by a remethylation disorder, even when the clinical presentation is milder than expected.

Keywords: Vitamin B12 Intracellular Metabolism; CblE Disease; Late Onset; Hyperhomocysteinemia; Macrocytic Anemia

References

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Citation

Citation: Francesco Porta.,et al. “Unusual Presentation of Remethylation Disorders: A Case of Later Onset CblE Deficiency”. Acta Scientific Paediatrics 4.1 (2021): .

Copyright

Copyright: © 2021 Francesco Porta.,et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.