 Hi, my name is Dr. Kim Boycott and this is Dr. Sarah Sawyer, and we are clinician investigators at the Children's Hospital of Eastern Ontario in Canada. The hospital sequencing is a diagnostic tool for pediatric ontenitaxia. We were inspired to write it by the high number of known diagnoses we made in pediatric patients with ataxia who underwent whole axiom sequencing for what was suspected to be a novel disorder as part of the FORGE project. The FORGE project, which stands for Finding a Rare Disease Genes in Canada, focused on identifying novel disease genes for pediatric disorders. But what we found in this study was in fact that a large number of these patients actually had mutations in known disease genes. To explore this further, we retrospectively selected all patients from FORGE with the diagnosis of pediatric ontenitaxia, which ended up being 42 patients from the 28 families, and we further subdivided these patients into three groups. We had 17 families with more than one affected child, 10 children who were born taken salmonist parents, and 15 simplex patients with no family history of ataxia. All the families that participated in the study had standard of care genetic testing, which is available to them in Canada, and a diagnosis was not forthcoming. Of these 28 families, we were able to give a diagnosis to 13 of them, which is a diagnostic hit rate of 46%. Of the two families, we identified novel disorders, and of 38%, we identified a known disorder, which in retrospect was called for the correct genetic diagnosis for the patient. Ataxia is genetically and phenotypically heterogeneous and difficult to diagnose clinically. These results likely reflect the difficulty in accessing comprehensive clinical testing for this heterogeneous presentation. The diagnostic success rate was broken down by categories as follows. For children who had an affected sibling with ataxia, the diagnostic hit rate was 43%. For children from consignments families, the diagnostic hit rate was 100%. And for the simplex cases, those patients with no family history, we were able to provide a diagnosis to families with 27% of cases. We did not identify a molecular etiology in 54% of the families we studied. This is likely due to multiple reasons, but most certainly reflects that many of these patients have multiple rare alleles in genes that were not currently known to cause ataxia, and solving these patients will require large-scale collaboration further down the line. I find this suggest that whole exome sequencing should likely be considered as a first-line diagnostic tool at ataxia, given the high success rate of 46%. This is anecdotally higher than Canadian physicians currently achieve using standardive care testing for patients with ataxia. Thank you for listening, and we hope you have been intrigued enough to read our paper.