Targeted Next-Generation Resequencing Panel in inherited ataxias

Hereditary cerebellar ataxias are a group of neurodegenerative diseases with clinical and genetic heterogeneity and variable age at onset. Next-Generation Sequencing technology has revolutionized the paradigm of clinical diagnostics, helping to end the long search for a genetic cause. A Targeted Next-Generation Resequencing Panel, containing 273 genes known or supposed to be related to hereditary ataxias, was performed in 39 index ataxic patients, recruited from the Ataxias Clinic of Neuroscience, Reproductive and Odontostomatological Science Department of the Federico II University. We identified eighteen probands out of 39 (46%) carrying pathogenic variants in ten different genes: SPG7 (five probands), PNPLA6 (three probands), SYNE1 (two probands), SETX (two probands), RNF216, ZFYVE26, ANO10, PMM2, ATP13A2 and TGM6 (one proband each). Variants of unknown significance were found in nine probands (23%). In the remaining twelve out of 39 cases (31%) no candidate variants or variants with unlikely pathogenicity were identified. Our findings suggest that after exclusion of repeat expansion ataxias, ataxia Targeted Next-Generation Resequencing Panel, could be a good first tier diagnostic line, when a specific single gene is not immediately suspected to be causative.