Translational Relevance of SCA1 Models for the Development of Therapies for Spinocerebellar Ataxia Type 1

Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant neurodegenerative dis-ease caused by the expansion of cytosine–adenine–guanine (CAG) repeats in the ataxin-1 (ATXN1) gene, leading to toxic gain-of-function of the ataxin-1 (ATXN1) protein. This narrative review systematizes the clinical and genetic aspects of SCA1 and discusses key molecular and cellular mechanisms: the ATXN1-CIC ataxin-1-Capicua complex (ATXN1-CIC), the role of serine 776 (Ser776) phosphorylation, interactions with 14-3-3 proteins, transcriptional dysregulation, and critically analyzes experimental models of the disease in vivo and in vitro. In addition, it presents a descriptive quantitative analysis of the literature on in vivo SCA1 models, conducted using a defined search methodology with a cut-off date of 23 November 2025. For each model, phenotypic markers, molecular signatures, and applicability to preclinical testing tasks are summarized. A comparison of the models reveals their complementarity and outlines optimal research trajectories, including omics approaches and prospects for targeted antisense oligonucleotide (ASO) therapy, RNA interference (RNAi), and genome editing. The result is a practical guide for selecting a model in accordance with specific hypotheses and translational objectives.