The suspicion that something was wrong started when the 1-year-old girl’s parents noticed she had trouble holding up her head. It was just the first of what would be many missed developmental milestones.
By the time she was 8, the little girl still couldn’t sit up on her own, hold a toy, or say hello. She had trouble sleeping more than an hour or two at a time. Several times each week, her body would suddenly stiffen, her eyes frozen to one side of her face, sometimes for hours. Known as an oculogyric crisis, it is a tragically standard symptom of AADC deficiency, an ultra-rare genetic disorder that starved her brain of dopamine and serotonin, essential molecules that allow brain cells to communicate with one another.