A gene in brain cells encodes a toxic protein (mHTT) that causes brain cells to die. Related Huntington’s symptoms emerge in middle-age as uncontrolled movements, balance problems, mood swings and cognitive decline. Researchers at Emory University School of Medicine have reversed Huntington’s disease symptoms in a mouse study. The researchers used gene therapy based on the AAV (ademon-associated virus) to guide enzymes into the striatum region of the brains of Huntington’s disease mice. The striatum is a region of the brain that controls body movement and motor function. Researchers then snipped part of a gene that was producing toxic proteins in the brains of the 9-month-old mice. Weeks later the aggregated proteins had almost disappeared and the motor abilities of the mice had improved. Compared with control mice, the CRISPR/Cas9-injected mice showed significant improvements on tests of motor control, balance and grip strength, although they did not recover to the point where they performed as well as control mice. Read more.