The National Institute of Mental Health of the National Institutes of Health has awarded Emory University School of Medicine a $3.6 million research grant to test schizophrenic patients for a recently discovered variation in the human genome. The project is led by Stephen T. Warren, PhD, Timmie Professor and chair of the Department of Human Genetics.
Schizophrenia is a severe and common psychiatric disorder that has a strong genetic predisposition. Despite the knowledge that genetic changes can lead to the disorder, however, few genes have been identified.
Recently, scientists have discovered an entirely new and previously unknown form of variation in the human genome, called "copy number variation," or CNV. This variation includes deletions and duplications of segments of DNA previously unrecognized in the general population. Scientists now believe every individual may carry as many as 100 CNVs. While these variations generally do not cause disease on their own, says Dr. Warren, in combination with other genetic changes and/or environmental factors they may well contribute to one's overall risk of disease.
Using cutting-edge technology available to only a few major research centers, the Emory project will screen a collection of 500 schizophrenic patients and 500 controls (individuals without schizophrenia) for CNV throughout the entire human genome.
The new technology uses "DNA chips," manufactured by NimbleGen Systems, Inc., that can compare DNA copy number differences in a reference genome to the genomes of the individuals being screened. Scientists can array 2.1 million locations in the genome, or about one in every 1,000 base pairs, on a single chip the size of a microscope slide. The project team will use the new Emory high performance computer cluster to analyze the data.
"By helping us identify CNVs, we believe this new kind of chip technology may lead us to the specific genes that influence schizophrenia and other major psychiatric diseases," Dr. Warren says.
The schizophrenia project is the first involvement in a disorder other than fragile X syndrome in over a decade for Dr. Warren, who is well know for his discoveries regarding this frequent form of mental retardation.
The Emory scientists are collaborating with Ann E. Pulver, ScD, professor of psychiatry and behavioral sciences at Johns Hopkins University, who collected the samples to be tested.