Antiviral protein causes genetic changes implicated in Huntington’s disease progression

People genetically susceptible to Huntington’s disease often see their movement, mood, and cognition decline slowly over time. The cause is related to expansion of repeating DNA units, in which specific strings of genetic code—in this case, a series of cytosine-adenine-guanine nucleotides, or CAG, on one strand of the DNA and cytosine-thymine-guanine, or CTG, on the complementary strand—begin to repeat over and over, expanding to as many as 40 to 120 copies.