Arima syndrome (AS) is a rare autosomal recessive disease characterized by severe psychomotor retardation, dysmorphic face, nystagmus, retinopathy, cystic kidney disease, and brain malformation. AS shares clinical and neuroradiological features with Joubert syndrome and related disorders, that is called ciliopathy. On brain magnetic resonance imaging (MRI), AS shows characteristic anomalies of the brainstem and cerebellum, such as the molar tooth sign (deformity of the brainstem isthmus and superior cerebellar peduncles) and cerebellar vermis hypoplasia.
