According to a recent study, scientists are closer than ever to understanding the cellular defects of Down syndrome—as well as how they might prevent the chromosomal disorder from progressing further in the womb.
During the study, which took place in a lab at the University of Massachusetts last year and was recently published in the science journal Nature, researchers used an RNA gene called XIST to "silence" one of two X chromosomes in female cells. Down syndrome—which affects 3,000 to 5,000 babies born worldwide each—occurs when the body produces an extra copy of the chromosome 21. But by attempting to reverse the affects of that extra chromosome, scientists could potentially erase its side effects (which include cognitive disability, early-onset Alzheimer's, and a greater risk of childhood leukemia, heart defects, and immune and endocrine system dysfunction).
To do so, scientists first obtained stem cells taken from fibroblast cells that were donated by a person with Down syndrome. They then inserted the XIST gene into a specific location on the chromosome and watched as it was rendered inactive.
As study researcher Jeanne Lawrence later told the Guardian, "This will accelerate our understanding of the cellular defects in Down's syndrome and whether they can be treated with certain drugs." Still, she was quick to note that researchers are still a long way from establishing official treatment for the disorder. "The long-range possibility—and it's an uncertain possibility—is a chromosome therapy for Down's syndrome," she said. "But that is 10 years or more away. I don't want to get people's hopes up."
Still, Dr. Brian Skotko, co-director of the Down Syndrome Program at Massachusetts General Hospital, is focusing on the optimism the study brings. As he told The Boston Globe recently, "It really is revolutionary, in terms of causing us all to rethink the one impossible thought: Can you make, functionally, that extra chromosome disappear?" he said. "I don’t think any of us thought it was possible or even within the current realm of scientific dreaming that we might one day be able to do it."