Affecting an estimated 100,000 people globally, cystic fibrosis (CF) cases stem from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. In the past several decades, scientists have successfully engineered various small-molecule therapies that lessen the severity of the disease. However there are still treatment challenges. Now, data from a new study in a cell model demonstrates that a gene therapy can successfully repair an “untreatable” mutation associated with a particularly severe form of the disease. Details of the potential therapy are published in a new Science Translational Medicine paper titled “Functional correction of the untreatable CFTR 1717-IG>A mutation through mRNA- and sgRNA-optimized base editing.” Many current therapies benefit patients with the most common disease-associated mutation, F508del. However they often have little effect on patients who harbor other types of mutations. For example, some patients have a mutation named 1717-1G>A, which is relatively common but doesn’t have any approved therapies due to being a splicing mutation that results in little to no protein production. In fact, “about 10% of people with CF do not qualify for any of the available CFTR modulator therapies, particularly those people with severe splicing mutations that result in frameshifts and the formation of premature termination codons.” The 1717-1G>A mutation is the target of the therapy described in the paper, which was written by scientists from the University of Trento and their collaborators elsewhere. Specifically, the team developed an “adenine base editing strategy to efficiently correct the 1717-1G>A mutation,” they wrote in Science Translational Medicine.…
