There are two common polymorphic genetic variants of the MTHFR gene that can lead to impaired functioning of this enzyme resulting in hyperhomocysteinemia [12]; The most common of these genetic variants is the 677C>T polymorphism (C-to-T substitution at nucleotide 677) which encodes a thermolabile enzyme that is less active at high temperatures. The gene discussed is MTHFR; the disease is hyperhomocysteinemia.