POSTED: 1501 GMT (2301 HKT), November 24, 2006

ATLANTA, Georgia (CNN) -- Researchers say they have developed an enhanced map of the human genome that could yield breakthroughs in understanding the genetic origins of illnesses such as heart disease, Alzheimer's and various forms of cancer.

The map, charted by an international team of researchers, shows genetic variations in the general population. That will provide researchers in labs around the world the landscape for comparing the genetics of disease, said Dr. Stephen Scherer, one of the researchers who took part in the study.

The more than 20,000 genes in the human body determine our gender, the color of our hair and how tall we are. For the most part we're pretty similar, but the new research -- published in the journal Nature -- suggests that the complexity of our differences may one day help determine who is at risk for disease.

Scherer, one of the study's authors, said the new map is a "wake-up call" that will change the way scientists look at all genetic studies in the future.

In 2000, researchers presented working drafts for more than 90 percent of the 3.1 billion genetic elements or "letters" that make up who we are by mapping key chromosomes, including those which contain vital information about kidney disease, certain cancers, hypertension and diabetes. New technology helped Scherer's team update these drafts and provide a 3-dimensional view of the strands of DNA.

"The old study was like a road map and you couldn't see where the road was going because of too many folds in the map," he said. "New technology allows us to scan a genome and get a dimensional view, like a Google Earth view."

Researchers from Canada, Europe, the United States and Japan compared DNA from 270 people with Asian, African and European ancestry and found large blocks of DNA that, when unraveled, could help determine an individuals' susceptibility to various disorders.

"When you find a disease chain, it can help you perform diagnostics very important for life planning," he said.

The study also found that the genetic differences in our individual DNA are greater than originally thought. For example, it is not uncommon to find in some people large sections of DNA moved to a different location, or missing altogether.

Researchers are already in the process of furthering the study. Over the next two years scientists plan to monitor 1,000 people from a range of populations worldwide, with the hopes of either having a more specific map or confirming what is already available.

"From a scientific perspective, it will change the way people study the human genome. I think this will push science up to the next level," Scherer says.

http://edition.cnn.com/2006/HEALTH/11/24/genome.disease/index.html