Aromatic L-amino acid decarboxylase (AADC) is an enzyme responsible for the final step in the synthesis of neurotransmitters dopamine and serotonin. AADC deficiency is a rare genetic disorder. Taiwanese carry a high prevalence of AADC deficiency due to the founder mutation IVS6+4 A>T, and patients usually die before the age 5-6 years due to severe motor dysfunction.~Gene therapy with adeno-associated virus (AAV) serotype 2 (AAV2) driven human AADC (hAADC) has been tested in both animal models and Phase I clinical trials of Parkinson disease. We have done a compassionate treatment of 8 patients with AADC deficiency by AAV2-hAADC and demonstrated a result that among the treated patients, 4 could stand with support, 3 could sit with support, and there was no virus-associated toxicity. The longest follow up has exceeded 4 years.~This study is to prove the safety and efficacy of AAV2-hAADC treatment for patients with Aromatic L-amino acid decarboxylase (AADC) deficiency.
This Phase I/II trial is to prove the efficacy and safety of AAV2-hAADC to treat patients with AADC deficiency.