Israeli, U.S. scientists find risk gene

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JERUSALEM — Israeli and U.S. researchers have isolated a gene linked to a specific personality trait — risk-taking.

The gene, called D4DR (fourth dopamine receptor gene) and located on the 11th chromosome, is said to be responsible for 10 percent of people's novelty-seeking or adventurous behavior.

Doctors at Soroka Hospital and the Beersheva Mental Health Center and at Jerusalem's Herzog Memorial-Ezrat Nashim Hospital, who tested 124 healthy Israelis, made the discovery. Doctors from the U.S. National Cancer Institute also pinpointed the gene on 300 people of various ethnic groups at the University of Maryland.

Prof. Haim Belmaker of Beersheva, who adapted a 100-question personality test developed in the United States to identify risk-taking behavior, said Monday that it was "even more important" that the U.S. team, which included Dr. Jonathan Benjamin of Soroka, backed up the Israeli findings.

"Scientists often make a discovery that does not prove itself in subsequent studies," he said, "but in this case, it repeated itself in an entirely different population."

People who score low on the novelty-seeking test tend to be exploratory, fickle, excitable, quick tempered, and extravagant, while those who score high are more stoic, loyal, reflective, frugal, rigid, and even-tempered.

Dr. Richard Ebstein, head of the research department at Herzog Hospital, said the D4DR gene was discovered in the United States in 1991.

"Its functioning is expressed in the limbic part of the brain — the section involved in emotions — and binds with high affinity to clozapine, a drug used to treat schizophrenia."

Belmaker said he was "very pleased" that the gene is "responsible for only 10 percent of such behaviors, since this has the smell of something real; it's complicated and hard to explain."