21/07/2025
In a groundbreaking study published in early 2025, Japanese scientists from Mie University successfully used CRISPR-Cas9 gene editing technology to remove the extra copy of chromosome 21 — the genetic cause of Down syndrome — from human cells. The research was conducted entirely in vitro, using both induced pluripotent stem cells (iPSCs) and fibroblasts taken from individuals with Down syndrome. The team developed an allele-specific approach to target and eliminate only the extra chromosome while preserving the other two copies, one from each parent.
The researchers observed that after the extra chromosome was removed, the edited cells showed normalized gene expression and biological improvements. These included enhanced neurodevelopmental signaling, reduced cellular stress, improved mitochondrial function, faster proliferation, and lower levels of reactive oxygen species. While the editing efficiency ranged from 13% to about 30% with additional DNA repair suppression, the findings represent a critical advancement in understanding how trisomy 21 affects cells and how targeted correction might restore normal function.
Despite its promise, this research remains far from clinical application. No living organisms or embryos were edited, and serious challenges still exist—including off-target genetic effects, safe delivery methods to human tissues, and long-term consequences. Ethical considerations are also central to this work, raising questions about identity, disability, and the appropriate use of powerful genetic tools. Nonetheless, the study opens an exciting new frontier in chromosomal therapy, offering future hope for addressing genetic conditions at their root.
Image: Generative AI
