FRIDAY, Oct. 24 (HealthDay News) -- American and Dutch researchers believe they may have identified three genes tied to the development of schizophrenia.

The suspects are rare copy number variants, or CNVs -- deletions and duplications in the human genome that appear to interrupt genes associated with brain function. The three CNVs were common in the genetic makeup of 54 Dutch patients diagnosed with deficit schizophrenia, a severe chronic and debilitating form of the psychiatric disease.

"These genes were not implicated in schizophrenia before," researcher Roel A. Ophoff, an assistant professor with the Center for Neurobehavioral Genetics at University of California, Los Angeles, said in a university news release. "So next, we tested these three genes in a large follow-up study of more than 750 general-schizophrenia patients and 700 controls. And what surprised us is that roughly 1 percent of schizophrenia patients harbor these genomic deletions."

The findings were published in the October issue of The American Journal of Human Genetics.

Scientists suspect that increased susceptibility to many other diseases may also be tied to such missing or duplicated segments of DNA.

Identifying these genes may provide a better insight into the biology of schizophrenia and why some people seem to be at a greater risk to develop the disease, Ophoff said.

"Another important step will be to assess the inheritance patterns of such CNVs," he said. "Since this is an inherited disease affecting approximately 1 percent of the population, this would be valuable toward establishing the clinical relevance of this important class of genomic variations."

More information

The National Institute of Mental Health has more about schizophrenia.