Hematologic abnormalities as a manifestation of a defect of intracellular cobalamin metabolism – report of five cases

Back
Elise Osterheld(1), Lutz Bindl(1), Wolfgang Boehm(1), Leon Bofferding(1), Jean Bottu(1), Christine Geron(1), Sandra Heck(1), Charlotte Pierron(1), Moritz Vogel(1), Linda De Meirleir(2), Geert Martens(2), Luc Regal(2), Emmanuel Scalais(1) Published in the journal : November 2018 Category : Hematology/Oncology

Summary :

Intracellular cobalamin (IC) and its two coenzymes, adenosylcobalamin and methylcobalamin, are necessary for the homeostasis of methylmalonic acid and homocysteine (Hcy). Defects of intracellular cobalamin metabolism are responsible for isolated methylmalonic aciduria (MMA), isolated increased Hcy, or both. MMA occurs when adenosylcobalamin, a cofactor of methylmalonic-CoA mutase, is low, thereby causing elevated MMA and decreased succinyl-CoA. A lack of methylcobalamin, a cofactor for methionine synthase, impairs the transformation of Hcy into methionine, thus leading to increased Hcy and low methionine levels.

Key words

Methylmalonic acid, cobalamin metabolism