The relationship between level of education and disease onset and progression in Spinocerebellar Ataxia types 1, 2, 3, and 6

BackgroundSocioeconomic factors such as educational attainment are associated with altered progression in numerous neurodegenerative disorders, but this relationship has not been fully explored in the context of spinocerebellar ataxias (SCAs). In previous work from several single-center studies, educational attainment was associated with modified onset or increased progression in SCA3 or SCA6. The relationship between such socioeconomic factors and onset or progression in SCAs has not previously been reported using data from studies conducted across multiple sites. MethodsWe evaluated data from the North America-based Clinical Research Consortium for the Study of Cerebellar Ataxias collected from 18 sites. We evaluated genetic, onset, severity, and self-reported educational data from patients with confirmed diagnoses of SCA types 1, 2, 3, or 6 and built linear mixed-effects models to evaluate the association between the level of education against disease onset and severity at a given timepoint. ResultsIn this cohort, we found that increased educational attainment was not associated with age of onset in any of the evaluated SCAs. However, in the context of severity at a given time point, increased education was strongly linked to reduced severity specifically in SCA3, but not in SCA types 1, 2, or 6. Results were consistent across several forms of robustness analysis and validation. ConclusionsIn a North American cohort, severity of SCA3, but not SCA1, SCA2, or SCA6 was found to be strongly inversely correlated with level of educational attainment. Further study in other cohorts would be useful.