What are the genetic changes related to aromatic l-amino acid decarboxylase deficiency ?
Mutations in the DDC gene cause AADC deficiency. The DDC gene provides instructions for making the AADC enzyme, which is important in the nervous system. This enzyme helps produce dopamine and serotonin from other molecules. Dopamine and serotonin are neurotransmitters, which are chemical messengers that transmit signals between nerve cells, both in the brain and spinal cord (central nervous system) and in other parts of the body (peripheral nervous system).  Mutations in the DDC gene result in reduced activity of the AADC enzyme. Without enough of this enzyme, nerve cells produce less dopamine and serotonin. Dopamine and serotonin are necessary for normal nervous system function, and changes in the levels of these neurotransmitters contribute to the developmental delay, intellectual disability, abnormal movements, and autonomic dysfunction seen in people with AADC deficiency.