They use a technique for tracking RNA in live cells called RNA-targeting Cas9 (RCas9). In a new study, published August 10 in Cell, the team takes RCas9 a step further: they use the technique to correct molecular mistakes that lead to microsatellite repeat expansion diseases, which include myotonic dystrophy types 1 and 2, the most common form of hereditary ALS, and Huntington's disease.

"This is exciting because we're not only targeting the root cause of diseases for which there are no current therapies to delay progression, but we've re-engineered the CRISPR-Cas9 system in a way that's feasible to deliver it to specific tissues via a viral vector," said senior author Gene Yeo, PhD, professor of cellular and molecular medicine at UC San Diego School of Medicine.

While DNA is like the architect's blueprint for a cell, RNA is the engineer's interpretation of the blueprint. In the central dogma of life, genes encoded in DNA in the nucleus are transcribed into RNA and RNAs carry the message out into the cytoplasm, where they are translated to make proteins.