Two sets of genes suspected of being involved in addiction are located on chromosome 17 in humans, according to Yale University researchers.

MedPage Today reported April 12 that researcher Joel Gelernter, M.D., and colleagues identified groups of opioid and non-opioid drug addicts and obtained DNA samples.

A genetic-linkage analysis found common genetic markers on the 17th chromosome among addicts of European descent. Previous studies also have found that chromosome 6 may be involved in opioid addiction.

"These results provide a first basis to identify genes for opioid dependence from a genome-wide investigation," Gelernter said. "Research in the laboratory now is focused on finding specific genes that modify risk for opioid dependence ... Once specific genes that increase or decrease risk are known, we will be in a better position to figure out exactly what the environmental factors might be and, perhaps, how they can be modified to protect people who are genetically at risk."

The study was published in the May 2006 issue of the American Journal of Human Genetics.