Gene Editing Corrects In Vitro a G > A GLB1 Transition from a GM1 Gangliosidosis Patient

CRISPR J. 2023 Feb;6(1):17-31. doi: 10.1089/crispr.2022.0045. Epub 2023 Jan 11.

Abstract

Ganglioside-monosialic acid (GM1) gangliosidosis, a rare autosomal recessive disorder, is frequently caused by deleterious single nucleotide variants (SNVs) in GLB1 gene. These variants result in reduced β-galactosidase (β-gal) activity, leading to neurodegeneration associated with premature death. Currently, no effective therapy for GM1 gangliosidosis is available. Three ongoing clinical trials aim to deliver a functional copy of the GLB1 gene to stop disease progression. In this study, we show that 41% of GLB1 pathogenic SNVs can be replaced by adenine base editors (ABEs). Our results demonstrate that ABE efficiently corrects the pathogenic allele in patient-derived fibroblasts, restoring therapeutic levels of β-gal activity. Off-target DNA analysis did not detect off-target editing activity in treated patient's cells, except a bystander edit without consequences on β-gal activity based on 3D structure bioinformatics predictions. Altogether, our results suggest that gene editing might be an alternative strategy to cure GM1 gangliosidosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • CRISPR-Cas Systems / genetics
  • Gangliosidosis, GM1* / drug therapy
  • Gangliosidosis, GM1* / therapy
  • Gene Editing
  • Humans
  • beta-Galactosidase / chemistry
  • beta-Galactosidase / genetics
  • beta-Galactosidase / metabolism

Substances

  • beta-Galactosidase
  • GLB1 protein, human