NGS in Hereditary Ataxia: When Rare Becomes Frequent

Int J Mol Sci. 2021 Aug 6;22(16):8490. doi: 10.3390/ijms22168490.

Abstract

The term hereditary ataxia (HA) refers to a heterogeneous group of neurological disorders with multiple genetic etiologies and a wide spectrum of ataxia-dominated phenotypes. Massive gene analysis in next-generation sequencing has entered the HA scenario, broadening our genetic and clinical knowledge of these conditions. In this study, we employed a targeted resequencing panel (TRP) in a large and highly heterogeneous cohort of 377 patients with a clinical diagnosis of HA, but no molecular diagnosis on routine genetic tests. We obtained a positive result (genetic diagnosis) in 33.2% of the patients, a rate significantly higher than those reported in similar studies employing TRP (average 19.4%), and in line with those performed using exome sequencing (ES, average 34.6%). Moreover, 15.6% of the patients had an uncertain molecular diagnosis. STUB1, PRKCG, and SPG7 were the most common causative genes. A comparison with published literature data showed that our panel would have identified 97% of the positive cases reported in previous TRP-based studies and 92% of those diagnosed by ES. Proper use of multigene panels, when combined with detailed phenotypic data, seems to be even more efficient than ES in clinical practice.

Keywords: Genesis; HA; TRP; cohort; diagnostic yield; exome sequencing; mutation; next-generation sequencing; targeted resequencing panel; variant.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • Exome Sequencing
  • Female
  • Genetic Testing
  • High-Throughput Nucleotide Sequencing*
  • Humans
  • Male
  • Middle Aged
  • Mutation
  • Spinocerebellar Degenerations / genetics*
  • Young Adult