Your individuality may not be determined by your genes, but rather by the sequences that surround and control them, say U.S. researchers.

They found that the interactions of those sequences with proteins called transcription factors vary significantly among people and likely affect appearance, development and even a person’s risk of developing certain diseases.

The findings suggest that focusing exclusively on genes to learn what makes each person unique will yield an incomplete picture.

“We are rapidly entering a time when nearly anyone can have his or her genome sequenced,” Michael Snyder, chair of genetics at Stanford University School of Medicine, said in a university news release. “However, the bulk of the differences among individuals are not found in the genes themselves, but in regions we know relatively little about. Now we see that these differences profoundly impact protein binding and gene expression.”

Snyder and colleagues at Yale University studied humans, chimpanzees and yeast. Their findings are published online March 17 in the journal Nature and online March 18 in Science Express.

SOURCE: Stanford University, news release, March 18, 2010