Genetic Spectrum and molecular diagnosis of nystagmus in a spanish paediatric cohort

Introduction Nystagmus is a common presenting sign of early onset inherited retinal dystrophies. Identifying a genetic diagnosis for infantile nystagmus syndrome patients is crucial for providing appropriate treatment and genetic counselling. This study aimed to evaluate the genetic findings in paediatric patients with nystagmus assessed between 1st January 2020 and 31st December 2025. Methods A total of 94 children presenting with nystagmus underwent a detailed ophthalmologic evaluation including electrodiagnostic tests and were referred for genetic testing during the study period. Comprehensive genomic analysis was performed to identify pathogenic or likely pathogenic variants. Results Of the 94 patients, 30 (32%) were found to have a pathogenic or likely pathogenic genetic variant. The most frequently implicated genes were PAX6, NDP , TYR , CNGA3 , RS1 and FRMD7 . These findings reflect the genetic heterogeneity of paediatric nystagmus and underscore the importance of targeted genetic evaluation in affected individuals. Conclusion A significant proportion of children with nystagmus have identifiable genetic causes, with mutations in PAX6 , NDP, TYR , CNGA3 , RS1 and FRMD7 being the most common in our cohort. Early genetic diagnosis can guide clinical management, inform prognosis, and enable genetic counselling.