Methionine Adenosyltransferase I/iii Deficiency, also known as mat i/iii deficiency, is related to glycine n-methyltransferase deficiency and hypermethioninemia, and has symptoms including vomiting An important gene associated with Methionine Adenosyltransferase I/iii Deficiency is MAT1A (Methionine Adenosyltransferase 1A), and among its related pathways/superpathways are Metabolism and Peptide chain elongation. The drugs Lecithin and Racemethionine have been mentioned in the context of this disorder. Affiliated tissues include brain and bone marrow, and related phenotypes are intellectual disability and hyperreflexia