CRISPR Technology Shows Promise in Removing Extra Chromosomes in Down Syndrome: Study Finds - Video

Gene editing techniques may eventually allow trisomy to be treated at the cellular level, according to an in vitro proof-of-concept study, published in the PNA Nexus Journal.

Down syndrome is caused by the presence of a third copy of the 21st chromosome. The condition occurs in approximately 1 in 700 live births and is relatively easy to diagnose at early stages of development. However, there are no treatments.

Ryotaro Hashizume and colleagues use the CRISPR-Cas9 gene editing system to cleave the third chromosome in previously generated trisomy 21 cell lines derived from both pluripotent cells and skin fibroblasts. The technique can identify which chromosome has been duplicated, which is necessary to ensure the cell does not end up with two identical copies after removal, but instead has one from each parent.

The authors were able to remove duplicate chromosomes from both induced pluripotent stem cells and fibroblasts. Suppressing chromosomal DNA repair ability increased the rate of duplicate chromosome elimination.

Therefore, the researchers showed that the chromosomal rescue reversibly restores both gene expression and cellular phenotypes. The approach is not yet ready for in vivo application, however, in part because the current technique can also change the retained chromosomes. According to the authors, similar approaches could eventually be used in neurons and glial cells and form the basis of novel medical interventions for people with Down syndrome.

Ref:

Ryotaro Hashizume, Sachiko Wakita, Hirofumi Sawada, Shin-ichiro Takebayashi, Yasuji Kitabatake, Yoshitaka Miyagawa, Yoshifumi S Hirokawa, Hiroshi Imai, Hiroki Kurahashi, Trisomic rescue via allele-specific multiple chromosome cleavage using CRISPR-Cas9 in trisomy 21 cells, PNAS Nexus, Volume 4, Issue 2, February 2025, pgaf022, https://doi.org/10.1093/pnasnexus/pgaf022