Richard Poulin, father of a young girl with aromatic L-amino acid decarboxylase (AADC) deficiency, discusses the importance of an early diagnosis of the ultra-rare condition.

AADC deficiency is a rare genetic disorder that affects the nervous and musculoskeletal systems of young patients. It is caused by a defect in the dopa decarboxylase (DDC) gene, which leads to a reduction in the critical neurotransmitters dopamine, norepinephrine, epinephrine, and melatonin in the brain. 

As Mr. Poulin explains, once his daughter, Rylae, was diagnosed, techniques for managing her disease dramatically changed. Prior to a proper diagnosis, they assumed Rylae was experiencing seizures which led to her being given diazepam and other drugs that made her sleep for most of the day. Furthermore, without a diagnosis, Mr. Poulin says he was unsure how to handle her, especially during what he now recognizes as oculogyric crises (characterized by abnormal rotation of the eyeballs, muscle spasms, and uncontrolled head and neck muscle action). 

Once a diagnose was confirmed, they were able to monitor and handle their child more proactively to reduce the risk of further complications.

 Rylae was later part of a successful clinical trial involving gene therapy for her ultra-rare condition. 

For more information about AADC deficiency and Rylae’s experience with the gene therapy, visit