CANVAS: A New Genetic Entity in the Otorhinolaryngologist’s Differential Diagnosis

The biallelic inheritance of an expanded intronic pentamer (AAGGG)A retrospective descriptive study from an ataxia database comprising 500 patients.The study was performed at the Otorhinolaryngology Department of a hospital in the north of Spain.Specific genetic testing for CANVAS was performed in 13 patients with clinical suspicion of complete or incomplete syndrome. The clinical diagnosis was supported by quantitative vestibular hypofunction, cerebellar atrophy, and abnormal sensory nerve conduction testing.Nine of 13 (69%) patients met clinical diagnostic criteria for definite CANVAS disease. The first manifestation of the syndrome was lower limb dysesthesia in 8 of 13 patients and gait imbalance in 5 of 13. Eleven of 13 (85%) patients were carriers of the biallelic (AAGGG)A genetic cause of CANVAS has recently been discovered. We propose genetic screening for biallelic expansions of the AAGGG pentamer of