ANO10-Related Spinocerebellar Ataxia: MDSGene Systematic Literature Review and a Romani Case Series

Abstract

Background: Biallelic pathogenic variants in the ANO10 gene cause autosomal recessive progressive ataxia (ATX-ANO10). Methods: Following the MDSGene protocol, we systematically investigated genotype–phenotype relationships in ATX-ANO10 based on the clinical and genetic data from 82 published and 12 newly identified patients. Results: Most patients (>80%) had loss-of-function (LOF) variants. The most common variant was c.1150_1151del, found in all 29 patients of Romani ancestry, who had a 14-year earlier mean age at onset than patients homozygous for other LOF variants. We identified previously undescribed clinical features of ATX-ANO10 (e.g., facial muscle involvement and strabismus) suggesting the involvement of brainstem pathology, and we propose a diagnostic algorithm that may aid clinical ATX-ANO10 diagnosis. Conclusions: The early disease onset in patients with c.1150_1151del may indicate the existence of genetic/environmental disease-modifying factors in the Romani population. Our findings will inform patient counseling and may improve our understanding of the disease mechanism. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.