A child had poor attention, delayed speech, fatigue, ASD-related records, upward eye movements, and abnormal walking. His MRI and EEG were normal. Early genetic testing was negative. But after walking more than 200 meters, his body began to “lock up.” This video tells the real medical detective story of AADC deficiency, a rare inherited neurotransmitter disorder caused by problems in DDC, the gene that encodes aromatic L-amino acid decarboxylase. When this enzyme does not work properly, the body cannot efficiently produce dopamine and serotonin, affecting movement, sleep, behavior, autonomic function, and development. We explain how AADC deficiency can resemble autism spectrum disorder, ADHD-like attention problems, cerebral palsy, seizure-like episodes, fatigue, and developmental delay—and why diagnosis may require CSF neurotransmitter testing, DDC gene analysis, and plasma AADC enzyme activity. This video is for medical education only and does not replace professional medical advice, diagnosis, or treatment.
