Homocysteinemia, also known as hyperhomocysteinemia, is related to homocystinuria due to deficiency of n -methylenetetrahydrofolate reductase activity and homocystinuria. An important gene associated with Homocysteinemia is MTHFR (Methylenetetrahydrofolate Reductase), and among its related pathways/superpathways are Metabolism of water-soluble vitamins and cofactors and One-carbon metabolism and related pathways. The drugs Hydrochlorothiazide and Amlodipine have been mentioned in the context of this disorder. Affiliated tissues include endothelial and kidney, and related phenotypes are Increased shRNA abundance and homeostasis/metabolism