Investigators came to their findings after analyzing DNA variations in 4,200 people with schizophrenia and 3,800 healthy control subjects and matching those variations to symptoms in individual patients.
In doing so, they identified distinct gene clusters that seem to cause eight separate types of the disorder, each with its own particular symptoms.
“What we’ve done here, after a decade of frustration in the field of psychiatric genetics, is identify the way genes interact with each other, how the ‘orchestra’ is either harmonious and leads to health, or disorganized in ways that lead to distinct classes of schizophrenia,” said senior investigator C. Robert Cloninger, MD, PhD, the Wallace Renard Professor of Psychiatry and Genetics at the Washington University School of Medicine in St. Louis.”
“Among patients who experienced hallucinations or delusions, specific genetic variations identified by researchers demonstrated 95% certainty of schizophrenia. That certainty extended to a full 100% for the gene variations researchers identified in patients with disorganized speech and behavior.
Overall, researchers found 42 clusters of genetic variations that increased a person’s risk of schizophrenia between 70% and 100%.
Researchers hope their findings will lead to improved diagnosis and treatment of schizophrenia.
“People have been looking at genes to get a better handle on heart disease, hypertension, and diabetes, and it’s been a real disappointment,” Dr. Cloninger said. “Most of the variability in the severity of disease has not been explained, but we were able to find that different sets of genetic variations were leading to distinct clinical syndromes. So I think this really could change the way people approach understanding the causes of complex diseases.”