University of Iowa researchers have learned more about a genetic variation that is a small risk factor for a mild form of schizophrenia yet also is associated with improved overall survival.

The findings, which appear online in the American Journal of Medical Genetics, could help lead to treatments for schizophrenia and even other illnesses, and ways to leverage the gene variation's advantages. An abstract of the article is available at http://www3.interscience.wiley.com/cgi-bin/abstract/114112711/ABSTRACT.

This HOPA12pb gene variation advance drew on a genetic database that was about five times larger than sample sizes used in previous research, said Robert Philibert, M.D., Ph.D., associate professor of psychiatry in the UI Roy J. and Lucille A. Carver College of Medicine and the study's co-author.

"The study used the National Institute of Mental Health's largest publicly available sample, and thus it provides even more convincing evidence that the gene variation is worth studying," Philibert said.

The genetic variation causes a change in the portion of the protein that regulates the development of dopamine-releasing neurons. Antipsychotic drugs work by blocking dopamine, but drug treatments have limited success, and so scientists seek other ways to treat patients.

The team analyzed the genetic data of 900 European-Americans and found the HOPA gene variation in 22 individuals. Although the gene variation accounts for only an estimated .3 percent of all schizophrenia, nearly three of every 100 Caucasians have the gene variation.

"Most mutations associated with psychosis are found in only one in 10,000 or one in 100,000 individuals, and so these mutations do not lend themselves as study models," Philibert said. "HOPA is a relatively common mutation and that makes it valuable to study."

Philibert said that be
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Contact: Becky Soglin
becky-soglin@uiowa.edu
319-335-6660
University of Iowa
13-Feb-2007