Something to sink your teeth into.

A 21-year-old Kuwaiti man had cerebral palsy, retinitis pigmentosa, hypertension, and renal failure. His younger brother and sister displayed similar findings. Ocular motility examination disclosed aperiodic alternating skew deviation in the patient and his younger brother. Magnetic resonance imaging showed hypoplasia of the superior cerebellar vermis with a "molar tooth" sign. Genetic testing confirmed an AHPI gene mutation on chromosome 6p23.3 in the patient and his siblings, confirming the diagnosis of Joubert syndrome. This case demonstrates the need to consider the diagnosis of Joubert syndrome in adults with retinitis pigmentosa or familial alternating skew deviation.