HistoryA 13-year-old girl was born to consanguineous parents. She presented with mild intellectual impairment, convergent strabismus, horizontal gaze palsy, and bilateral abducens palsy. Vertical gaze was preserved, and no abnormalities suggesting facial paralysis were noted. In addition, she reported progressive back pain since she was 5 years old. Other symptoms were denied. No medications or related drugs had been administered thus far.