Session Information
Date: Monday, September 23, 2019
Session Title: Ataxia
Session Time: 1:45pm-3:15pm
Location: Les Muses, Level 3
Objective: To obtain survival estimates for SCA2 patients based on the age at onset and CAG repeats length .
Background: Spinocerebellar ataxia type 2 (SCA2) is the second most frequent autosomal dominant ataxia worldwide, reaching its highest prevalence rate in Holguín province, Cuba. This neurodegenerative disorder is caused by the unstable expansion of a CAG repeat in the first exon of the ATXN2 gene, which encodes the ancient starvation factor Ataxin-2, which suppresses growth via mTORC1 signaling and mRNA translation. Even when SCA2 is a disorder with high mortality and morbidity, there is little information about survival or disease duration in affected patients.
Method: Clinical and molecular data were obtained concerning 429 alive and 147 deceased SCA2 cases. The CAG repeat number at the ATXN2 locus was assessed by PCR followed by polyacrilamide gel electrophoresis. Overall survival and survival after disease onset estimates were obtained by using Kaplan-Meier survival analysis, given a specific age at onset category or CAG repeat expansion.
Results: Strong to moderate highly significant linear correlations were obtained between overall survival and age at onset (r=0.855; p<0.001) or CAG repeats number (r=-0.696; p<0.001) among deceased SCA2 individuals. Survival after disease onset was highly significantly correlated with CAG repeats number (r=-0.364; p<0.001) but not with the age at onset (r=0.129; p=0.12). Probabilistic estimates were obtained for survival based on the age at onset and CAG repeats length.
Conclusion: A substantial contribution is provided to further describing the negative impact of disease on patient’s survival, and the importance of the CAG repeats length as the main genetic factor involved in determining survival in SCA2 patients. These findings are important for a better understanding of the natural history of the disease and may be relevant in evaluating the long-term impact of future therapeutic interventions.
To cite this abstract in AMA style:
L. Almaguer-Mederos, R. Aguilera-Rodríguez, Y. González-Zaldívar, D. Almaguer-Gotay, D. Cuello-Almarales, Y. Vázquez-Mojena, L. Velásquez-Pérez. Survival estimates for Spinocerebellar Ataxia type 2 based on age at onset and CAG repeats length [abstract]. Mov Disord. 2019; 34 (suppl 2). https://www.mdsabstracts.org/abstract/survival-estimates-for-spinocerebellar-ataxia-type-2-based-on-age-at-onset-and-cag-repeats-length/. Accessed June 14, 2025.« Back to 2019 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/survival-estimates-for-spinocerebellar-ataxia-type-2-based-on-age-at-onset-and-cag-repeats-length/