There are currently three hypothesis for demyelination in the Central Nervous System (CNS) of methylenetetrahydrofolate reductase (MTHFR) deficient patients. These three possible mechanisms are: inadequate methionine synthesis, a deficiency of S-adenosylmethionine or accumulation of toxic intermediates from the elevated levels of homocysteine. This pathway includes all three of these possible mechanisms. This pathway was inspired by Chapter 10 of the book of Blau(ISBN 3642403360 (978-3642403361)) and the paper by [Prasad et al. 2011](https://www.ncbi.nlm.nih.gov/pubmed/21778025).
For an overview of disorders related to folate metabolism and transport, please see [WP4259](https://www.wikipathways.org/index.php/Pathway:WP4259).