Hyperhomocysteinemia (HHcy) is a metabolic disorder caused by improper removal and/or accumulation of Hcy most commonly arising from low dietary intake of folate or vitamin B12, or decreases in 5-methyltetrahydrofolate homocysteine methyltransferase (Mtr) and cystathionine β-synthase (Cbs) genes [15]. The gene discussed is MTR; the disease is metabolic disease.