MTRR (Methionine Synthase Reductase): MTRR is an enzyme that plays a vital role in regenerating methylcobalamin, supporting the continuous activity 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 may contribute to developmental and neurological complications. Understanding MTRR function offers insights into potential therapies for genetic disorders.