Genetic Heterogeneity in Hereditary Ataxias: Implications for Diagnosis and Treatment

Strategic Insights -

A new study published in the Annals of Indian Academy of Neurology has shed light on the genetic heterogeneity of hereditary ataxias, a group of disorders characterized by clinical manifestations of cerebellar degeneration. Researchers from India analyzed 230 patients with progressive ataxias and identified a total of 180 variants, including 8% loss-of-function mutations and 39% nonsynonymous substitutions. The study found that pathogenic or likely pathogenic variations were present in 14 subjects (6%), with mutations most frequently observed in the ATM and AFG3L2 genes. The findings emphasize the need for a broader panel of genetic testing to identify diagnostic variations and underscore the importance of functional studies for improving genetic diagnosis in hereditary ataxias.

Key Takeaways:

  • The study analyzed 230 patients with progressive ataxias and identified a total of 180 variants, including 8% loss-of-function mutations and 39% nonsynonymous substitutions.
  • Pathogenic or likely pathogenic variations were present in 14 subjects (6%), with mutations most frequently observed in the ATM and AFG3L2 genes.
  • The study found an increased burden of loss-of-function variation in patients compared to controls, with a major contribution from the ATM gene.
  • The researchers recommend a broader panel of genetic testing to identify diagnostic variations and highlight the importance of functional studies for improving genetic diagnosis.
  • The study emphasizes the genetic heterogeneity of hereditary ataxias, which has significant implications for diagnosis and treatment.

Statistics:

  • 230 patients with progressive ataxias were analyzed in the study.
  • A total of 180 variants were identified, including 8% loss-of-function mutations and 39% nonsynonymous substitutions.
  • 14 subjects (6%) had pathogenic or likely pathogenic variations.
  • The ATM and AFG3L2 genes had the most frequently observed mutations.
  • The study found an increased burden of loss-of-function variation in patients compared to controls, with a major contribution from the ATM gene.

Sources:

  • Jupita Handique, Pooja Sharma, Kriti Kashyap, et al. "Diagnostic Yield and Genetic Burden Analysis of Frequently Mutated Genes in Progressive Ataxia." Annals of Indian Academy of Neurology, 2025.
  • Wolters Kluwer Medknow Publications, Wolters Kluwer India Pvt Ltd, A-202, 2ND Flr, Qube, C T S No 1498A-2 Village Marol, Andheri East, Mumbai, Maharashtra, India.