👤 Ludger Schöls

Spinocerebellar Ataxia Type 3 (SCA3) is an autosomal dominant neurodegenerative Polyglutamine (polyQ) disease, caused by a cytosine-adenine-guanine (CAG) repeat expansion in the ATXN3 gene, resulting in an expanded polyQ tract in the Ataxin-3 protein. Although the principal genetic determinant of the age at onset (AAO) in polyQ diseases is the expanded CAG repeat length, variability in AAO has been explained only partly, suggesting the existence of additional genetic modifiers. Apolipoprotein E (APOE) haplotypes are associated with the risk of numerous, especially degenerative, diseases. Investigations of a potential role of APOE haplotypes in AAO variability of SCA3 have resulted in partly conflicting outcomes, with current evidence lacking power and patient diversity. To further clarify a potential modifying effect of APOE haplotypes on the AAO in SCA3, over 800 SCA3 patients from different origins were enrolled in the present study. While we did not find an association of common APOE haplotypes or singular APOE alleles with AAO in SCA3, rare ε4 homozygosity was linked to an earlier AAO in individuals from Brazil, with a mean disease onset six years earlier than carriers of other APOE haplotypes. Our study thus provides initial evidence for a relevant impact of ε4 homozygosity on disease onset in SCA3 and provides evidence supporting an allele-dosage effect of APOE ε4 in polyQ diseases. Show less

Spinocerebellar ataxia type 3 (SCA3) is one of the most common dominantly inherited ataxias worldwide. Despite research advances, no approved disease-modifying treatment exists, and management focuses on symptom alleviation and functional capacity maximization. Symptomatic treatment guidelines are scarce, leaving decisions to physicians' discretion. The lack of studies on SCA3 symptom management hinders therapy standardization. The aim of this study was to investigate medication-usage patterns among SCA3 mutation carriers and controls included in the multicentric European Spinocerebellar Ataxia Type-3/Machado-Joseph Disease Initiative (ESMI) cohort. We conducted a retrospective cross-sectional analysis of the medication taken by ESMI participants enrolled in the study between 2016 and 2023. Medication being used at the most recent follow-up visit available was categorized according to the Anatomical Therapeutic Chemical system. Comparisons between groups were performed using nonparametric tests for continuous variables and Fisher's exact test for categorical variables. In addition, a retrospective longitudinal analysis was conducted to study the impact of medication subclasses on disease progression, using linear mixed-effects models adjusted for relevant covariates. A total of 474 participants were included, comprising 344 SCA3 mutation carriers and 130 controls. Compared with controls, SCA3 subjects took more vitamins, mineral supplements, muscle relaxants, and medications targeting the nervous system. Psychoanaleptics and vitamins were introduced early in the disease course, whereas most other subclasses were initiated in mid-to-late stages, coinciding with the onset of neurological symptoms. Substantial disparities in medication usage were observed across the study centers. None of the medication subclasses commonly used by patients with SCA3 showed a significant impact on disease progression. This is the first study to explore medication usage patterns in SCA3 mutation carriers. Our study provides a comprehensive overview of the medications administered in SCA3 and underscores the importance of collaborative efforts toward achieving standardized clinical practices in the management of this disease. Show less

We identified a marker in LINGO1 showing genome-wide significant association (P = 1.2 x 10(-9), odds ratio = 1.55) with essential tremor. LINGO1 has potent, negative regulatory influences on neuronal survival and is also important in regulating both central-nervous-system axon regeneration and oligodendrocyte maturation. Increased axon integrity observed in Lingo1 mouse [corrected] knockout models highlights the potential role of LINGO1 in the pathophysiology of ET [corrected] Show less