An iPSC-derived midbrain dopaminergic neuronal model of aromatic amino acid decarboxylase (AADC) deficiency gives insight into neurodevelopmental disease features

Aromatic L-amino acid decarboxylase (AADC) deficiency is a complex inherited neurological disorder of monoamine synthesis which results in dopamine and serotonin deficiency. Affected patients have severe cognitive and motor delay, recurrent oculogyric crises, a complex movement disorder and high risk of premature mortality. Standard pharmacological treatment provides limited clinical benefit. Promising gene therapy approaches are emerging, though may not be either suitable or easily accessible for all patients. In order to better characterize the underlying disease pathophysiology and guide precision therapies, we generated a patient-derived midbrain dopaminergic (mDA) neuronal model of AADC deficiency from induced pluripotent stem cells (iPSCs). The neuronal model recapitulates key disease features, including absent AADC enzyme activity and dysregulated dopamine metabolism. We observed developmental defects affecting synaptic maturation and neuronal electrical properties. Overall design: Aged-matched healthy Control and 2 AADC deficiency patients iPSCs-derived midbrain dopaminergic neurons (3 biological replicates each).