When 23-year-old Miguel Ruiz visits his doctor, he knows his extra chromosome means his body works differently than most people. But until now, scientists didn't have a clear picture of exactly how or why those differences show up differently in each person with Down syndrome.
A new study from the Linda Crnic Institute for Down Syndrome at the University of Colorado Anschutz Medical Campus in Aurora is changing that. Researchers there have created the most detailed biological map ever made of how Down syndrome affects the body — and why some people with the condition face additional health challenges while others don't.
The team, led by executive director Dr. Joaquín Espinosa, analyzed hundreds of blood samples from people with Down syndrome as part of something called the Human Trisome Project. That's one of the biggest studies of its kind anywhere, gathering clinical information, biological data, and samples from thousands of participants.
What they found was striking. The researchers mapped changes in gene activity, protein levels, chemical signals in the blood, and immune cells across 100 different health conditions. The result is essentially a detailed atlas showing how having an extra copy of chromosome 21 — the genetic quirk that causes Down syndrome — ripples through the entire body in ways that are unique to each person.
"We know that no two individuals with Down syndrome are the same from a clinical standpoint, and now we can understand how this uniqueness is reflected in their molecular, metabolic and immune profiles," Dr. Espinosa said.
One of the most surprising discoveries had to do with obesity. The researchers found that people with Down syndrome who also have obesity show dramatic changes in their hormone systems, metabolism, and inflammation throughout the body — much bigger effects than in people without Down syndrome who have obesity.
The study also uncovered telltale biological patterns, called biosignatures, that show immune system problems and heart stress persisting throughout life in people who were born with certain heart defects. This matters because it suggests doctors could potentially use simple blood tests to monitor these long-term effects — catching problems early instead of waiting for symptoms to appear.
Lead author Dr. Micah Donovan called the number of discoveries "spectacular." The team expects this data set to fuel research for years to come, helping scientists dig into why people with Down syndrome experience such a wide range of health outcomes.
The research relied on participants sharing their medical histories and records — something the team emphasized as essential. "Thanks to the contributions from research participants and their families, we have gained much-needed knowledge," said Dr. Angela Rachubinski.
The ultimate goal? Personalized medicine. Instead of one-size-fits-all treatments, doctors could someday tailor care to each person's unique biological profile — understanding which health patterns to watch for and which interventions might work best. The Crnic Institute team is already working on follow-up studies to turn these findings into real-world tools that can help people like Miguel live healthier lives.