Hypermethioninemia, also known as hepatic methionine adenosyltransferase deficiency, is related to methionine adenosyltransferase i/iii deficiency and glycine n-methyltransferase deficiency, and has symptoms including vomiting An important gene associated with Hypermethioninemia is MAT1A (Methionine Adenosyltransferase 1A), and among its related pathways/superpathways are Metabolism and Regulation of expression of SLITs and ROBOs. The drugs Lecithin and Racemethionine have been mentioned in the context of this disorder. Affiliated tissues include liver and eye, and related phenotypes are Decreased shRNA abundance and liver/biliary system