Down Syndrome Research Key to Advances in Genetic Science

Newswise — The study of Down syndrome has played an important role in the advancement of the science of genetics.

So say two scientists in the February 2005 issue of the scientific journal Nature Reviews Genetics.

"Many advances in genetics, especially human genetics, were pioneered by studies of chromosome 21," say Dr. David Patterson, director, and Dr. Alberto C.S. Costa, research professor, of the University of Denver's Eleanor Roosevelt Institute. "And the interest in this chromosome was, and continues to be, driven by its causal role in Down syndrome."

Since the late 1950s it has been known that abnormalities in chromosome 21 cause Down syndrome. Thus chromosome 21 has been studied for a long time.

Down syndrome is a genetic disorder that affects the brain and many other body systems. It occurs in about one of 800 births. Advances along several disciplines of science—but especially in genetics—have led to progress in the descriptions of the traits of Down syndrome, say Dr. Patterson and Dr. Costa in their article titled "Down Syndrome and Genetics—A Case of Linked Histories."

At the same time that Down syndrome research has sparked advances in genetic science, progress also has been rapid in the care of people who have the condition, note Dr. Costa and Dr. Patterson, also both affiliated with the department of psychiatry at the University of Colorado Health Sciences Center.

"Just over 35 years ago, the median age of death for a person with Down syndrome was one year," points out Dr. Costa. "Now it is 49 years of age. In addition, today if a person with Down syndrome reaches his or her first birthday, the median life expectancy rises to 60 years of age."

Nearly all children with Down syndrome are now raised at home by their parents instead of being put into institutions and they attend schools in inclusive or semi-inclusive settings. The authors credit advances in medical care and changing attitudes for the improvements.

One of the ways in which Down syndrome research has helped the entire field of genetic science is through the creation and wide distribution of the Ts65Dn mouse. This is a type of mouse created by scientists to model similarity to human genetics and is now a staple of genetic research. The Ts65Dn mouse originally was created to study Down syndrome.

General distribution of the Ts65Dn mouse among scientific researchers began only about 10 years ago and studies of its genes are leading to advances in the understanding of Alzheimer's disease among other conditions.

The goal of Down syndrome research today should be to improve the lives of people with the condition and their families, Dr. Patterson and Dr. Costa say. It is important now to quantify and define more specific traits associated with Down syndrome. Genetics has advanced to the point that it is now possible to look at entire biological systems.

"An attractive feature of this approach is that it can detect alterations in the expression of genes not on chromosome 21," Dr. Costa says.

"Because of the tools available today, it is not unreasonable to speculate that the disabilities associated with Down syndrome might be amenable to therapeutic interventions to help people maximize their potential," the researchers write.