21/07/2025
In a groundbreaking first, scientists have removed the extra chromosome responsible for Down syndrome from living human cells
Researchers in Japan, led by Dr. Ryotaro Hashizume at the National Cancer Center Research Institute in Tokyo, used CRISPR-Cas9 gene-editing to eliminate the third copy of chromosome 21 the root cause of Down syndrome. In more than 30% of the treated cells, this genetic correction restored normal chromosomal balance, marking the first time in history that the condition’s underlying genetic error has been directly and cleanly corrected.
Until now, treatments for Down syndrome have focused only on managing symptoms. This research signals a radical shift: tackling the cause, not just the consequences. The precision of the CRISPR tool allowed scientists to remove only the extra chromosome, without damaging the vital pair that remains. Though the treatment is still in its early stages and years away from clinical use, it represents a major milestone in the fight against chromosomal disorders once considered untouchable.
This breakthrough could change how we think about genetic conditions from unchangeable traits to curable imbalances. It’s not just about Down syndrome; it opens the door to a new era where genetic therapies might one day correct other chromosomal abnormalities as well. Science has reached a moment once thought impossible where we don’t just study genetic disorders, we start rewriting them.
Credit: National Cancer Center Japan, CRISPR-Chromosome 21 Research Team, July 2025.
