By Meagan IngersonThe Daily Northwestern
Scientists at Evanston Northwestern Healthcare’s Research Institute are examining the genetic links to schizophrenia in what could be the largest U.S. study of the disease ever.
The current study is funded by an $11 million grant from the National Institutes of Health, which was awarded to the Research Institute, 1001 University Place, last October. Researchers estimate it will be the largest such experiment ever conducted in the U.S., with eight other sites in the U.S. and one in Australia contributing to the research.
“We’re working on an experiment that is quantitatively different,” lead researcher Dr. Pablo Gejman said. “Instead of looking at one gene, (we’re looking at) all the genes at one time.”
Schizophrenia, which occurs in about 1 percent of the world population, has been linked to both environmental and genetic factors.
Having a sibling or parent who suffers from schizophrenia increases a person’s chance of developing the disease to about 10 percent.
Gejman, a psychiatry professor at Feinberg School of Medicine, and his team previously discovered a link between the disease and a specific gene in a smaller-scale family study. This gene causes a person to experience hallucinations while under the influence of some drugs, such as LSD, and is thought to play a role in the hallucinations experienced by schizophrenics.
The new research aims to both replicate this finding and to identify other potentially linked genes.
“(Experts think) schizophrenia is caused by multiple genes, some that are much more prevalent in schizophrenics,” said Dr. Jill Morris, an assistant professor in pediatrics at Feinberg.
Morris, who works in schizophrenia research, said she plans to work on an offshoot of Gejman’s study. She and Feinberg Prof. Jubao Duan will examine linked genes in experiments with mice.
About 4,500 schizophrenic patients and 4,500 control subjects comprise the test group.
Gejman said the larger sample size will help researchers more precisely identify potential links to the disease.
“The most important characteristic (of schizophrenia) is that the effects are very small, so we need large samples,” he said.
The study was designed so that approximately one-third of participants are black, Gejman said. It will be the largest collection of black schizophrenic patients in the country, which is an underserved group in medical research, he said.
“The populations of different ancestry complement one another very well in a way that facilitates the search for genes,” Gejman said.
He said the different populations will allow researchers to identify “genetic markers that do not depend on ancestry, they depend on the disease.”
The larger sample size also increases the study’s chance of being replicated, Gejman said.
Technological challenges have also made confirming the previous genetic links to the disease difficult, psychology Prof. J. Michael Bailey said.
“When (the studies) first started to happen probably in the early ’90s or so, they tended not to replicate very well,” he said. “But the technology has grown so that I think the more recent findings are more likely to stand up over time.”
Gejman said he expects the study to be completed by the end of the year, but he does not yet know what potential effects it could have on the treatment of schizophrenia.
Reach Meagan Ingerson at [email protected].
