Pendular Nystagmus: a Novel Feature of ANO10-Related Disorders

ANO10-related ataxia is characterized by cerebellar and pyramidal signs, with prominent oculomotor abnormalities, including saccadic abnormalities, strabismus, and ptosis. While nystagmus is frequently observed, the specific subtype of horizontal pendular nystagmus has not been emphasized. This report describes two siblings with early-onset spastic-ataxia with horizontal pendular nystagmus, ultimately diagnosed with SCAR10. This report details the ocular abnormalities spectrum of ANO10-related ataxia by highlighting horizontal pendular nystagmus as a significant clinical feature in early-onset presentations. We also restate the importance of neurological examination, including detailed assessment of ocular movements, for accurate diagnosis and management of hereditary ataxias.