MTRR (Methionine Synthase Reductase): MTRR is an enzyme that plays a crucial role in regenerating methylcobalamin, supporting the continuous function of MTR in homocysteine metabolism. It is essential for maintaining proper methionine levels and normal DNA synthesis. Mutations in MTRR are associated with homocystinuria, which can lead to developmental and neurological complications. Understanding MTRR function provides insights into potential therapies for genetic disorders.