This study published in Nature team described a technique called twin prime editing (twinPE), this technique makes two adjacent prime edits to introduce larger sequences of DNA at specific locations in the genome with few unwanted byproducts. With further development, the technology could potentially be used as a new form of gene therapy to insert therapeutic genes in a safe and highly targeted manner to replace mutated or missing genes.

The researchers demonstrated the therapeutic potential of twinPE by editing, in human cells, a gene linked to Hunter syndrome, a rare genetic disorder. This disease is caused by an inversion of a specific 40,000 base pair long stretch of DNA. The team used twinPE to introduce an inversion of a similar length at the same site in the genome, showing how the method could be used to correct the disease-causing mutation. The team also used twin PE to precisely insert gene-sized DNA cargo of thousands of base pairs into therapeutically relevant sites in the genome.