Researchers at the Yerkes National Primate Center have genetically engineered monkeys to get Huntington’s disease (to test medicines), the first monkey model of a human disease made using transgenic technologies.

Transgenic animals are created using a recombinant DNA method to modify a genome. Researchers routinely splice human genes in and out of mice to give them diabetes, cancer, and heart disease, but they don’t have involuntary muscle movement, and it’s hard to measure their cognitive decline.

Transgenic monkeys with other human diseases, such as early onset Alzheimer’s or fragile X syndrome, are sure to follow, predict researchers.