What is the impact of education on Huntington's disease?

Authors


  • Relevant conflicts of interest/financial disclosures: This work is supported in part by grants from the Spanish Ministry of Health, FIS 2007/PI07025, CAM 0202/2006, and CIBER 2006/05/0059. “Registry” and other activities of the Euro HD Network are supported by the CHDI Foundation. Full financial disclosures and author roles can be found in the online version of this article.

Abstract

Huntington's disease (HD) is a neurodegenerative disease caused by a cytosine adenosine guanine (CAG) expansion in the huntingtin gene. The length of the triplet repeat is the most important factor in determining age of onset and the severity of the disease, but substantial variability of these parameters is attributed to other factors. To investigate the relationship between the years of education and the age at onset and the severity of the phenotype in patients with HD, we applied multiple linear regression analysis to examine the impact of education on the age at onset and the severity of the clinical scores assessed by the Unified Huntington's Disease Rating Scale (UHDRS) of 891 patients with HD from the multinational observational study “Registry” conducted by the European Huntintgton's Disease Network. The model was adjusted for CAG repeat length and age at the time of assessment. Patients with lengthier education exhibited earlier estimated age at onset but less severe clinical scores (motor = −3.6, P = 0.006; cognitive = 27.0, P < 0.001; behavioral = −3.0, P < 0.001; and functional capacity = 1.1 points, P < 0.001) than those with shorter education, after controlling for age and number of CAG repeats. These differences persisted throughout all quartiles of disease severity. An earlier recognition of symptoms and manifestations among the more educated patients could explain the earlier estimated age at onset in this group. The link between better clinical UHDRS scores and higher education might reflect a beneficial effect of education or its covariates on the course of HD. © 2011 Movement Disorder Society

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