AADC, or Aromatic L-Amino Acid Decarboxylase, is an enzyme that plays a crucial role in the synthesis of neurotransmitters. It catalyzes the conversion of aromatic L-amino acids, such as L-DOPA, into their corresponding amines, including dopamine and serotonin. This process is essential for proper brain function and mood regulation. Deficiency in AADC can lead to a rare genetic disorder known as AADC deficiency, which affects the production of these neurotransmitters. Symptoms may include developmental delays, movement disorders, and autonomic dysfunction. Early diagnosis and treatment are important for managing the condition and improving quality of life.