51ÊÓƵ

The human genome is a 3-billion letter instruction book, using a 4-letter DNA alphabet. Just a single typo can lead to a devastating disease. Imagine the ability to, like a copy editor, quickly fix DNA spelling errors so that the genetic words and sentences read flawlessly. 51ÊÓƵ scientists are getting close: they have developed a revolutionary new way to edit genomes precisely inside living cells, without even removing the DNA as was once necessary. Researchers are testing the value of this method, named CRISPR, for hundreds of applications. Some include creating malaria-resistant mosquitoes, and correcting gene errors in diseases known to be caused by one or just a few mutations. Recently, 51ÊÓƵ researchers successfully edited the disease-causing mutation in blood-forming cells taken directly from people with sickle-cell disease. These gene-edited cells survived when transplanted into mice, suggesting that such a treatment might be long-lasting or possibly even curative if tested in humans. If CRISPR could be targeted effectively to cells in a living person, then the thousands of genetic diseases that currently lack treatment might be cured.