Gene therapy for aromatic L-amino acid decarboxylase deficiency by MR-guided direct delivery of AAV2-AADC to midbrain dopaminergic neurons

Toni S. Pearson, Nalin Gupta, Waldy San Sebastian, Jill Imamura-Ching, Amy Viehoever, Ana Grijalvo-Perez, Alex J. Fay, Neha Seth, Shannon M. Lundy, Youngho Seo, Miguel Pampaloni, Keith Hyland, Erin Smith, Gardenia de Oliveira Barbosa, Jill C. Heathcock, Amy Minnema, Russell Lonser, J. Bradley Elder, Jeffrey Leonard, Paul LarsonKrystof S. Bankiewicz

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare genetic disorder characterized by deficient synthesis of dopamine and serotonin. It presents in early infancy, and causes severe developmental disability and lifelong motor, behavioral, and autonomic symptoms including oculogyric crises (OGC), sleep disorder, and mood disturbance. We investigated the safety and efficacy of delivery of a viral vector expressing AADC (AAV2-hAADC) to the midbrain in children with AADC deficiency ( Identifier NCT02852213). Seven (7) children, aged 4–9 years underwent convection-enhanced delivery (CED) of AAV2-hAADC to the bilateral substantia nigra (SN) and ventral tegmental area (VTA) (total infusion volume: 80 µL per hemisphere) in 2 dose cohorts: 1.3 × 1011 vg (n = 3), and 4.2 × 1011 vg (n = 4). Primary aims were to demonstrate the safety of the procedure and document biomarker evidence of restoration of brain AADC activity. Secondary aims were to assess clinical improvement in symptoms and motor function. Direct bilateral infusion of AAV2-hAADC was safe, well-tolerated and achieved target coverage of 98% and 70% of the SN and VTA, respectively. Dopamine metabolism was increased in all subjects and FDOPA uptake was enhanced within the midbrain and the striatum. OGC resolved completely in 6 of 7 subjects by Month 3 post-surgery. Twelve (12) months after surgery, 6/7 subjects gained normal head control and 4/7 could sit independently. At 18 months, 2 subjects could walk with 2-hand support. Both the primary and secondary endpoints of the study were met. Midbrain gene delivery in children with AADC deficiency is feasible and safe, and leads to clinical improvements in symptoms and motor function.

Original languageEnglish
Article number4251
JournalNature communications
Issue number1
StatePublished - Dec 2021


Dive into the research topics of 'Gene therapy for aromatic L-amino acid decarboxylase deficiency by MR-guided direct delivery of AAV2-AADC to midbrain dopaminergic neurons'. Together they form a unique fingerprint.

Cite this