Schizophrenia may consist of 8 genetic disorders

Researchers have attempted for years to understand schizophrenia, a mental disorder consisting of hallucinations, delusions, along with thought, movement and cognitive impairment. While may have theorized the condition was really the result of multiple conditions, new research now suggests eight specific genetic disorders that occur in a schizophrenia diagnosis.

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Because individuals with a family history of schizophrenia are at an increased risk for the disorder, researchers from Washington University felt genetics were the most reasonable starting point to find a cause. What they uncovered was that, out of the 83 genes previously linked to schizophrenia, there were actually 8 identifiable genetic diseases present, each with their own symptoms.

“Genes don’t operate by themselves,” said senior investigator Dr. C. Robert Cloninger, to MNT. “They function in concert much like an orchestra, and to understand how they’re working, you have to know not just who the members of the orchestra are but how they interact. 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.”

The way these genes interact is what ultimately results in an individual’s schizophrenia symptoms and their severity. For example, out of a test pool of nearly 10,000 individuals, experts were able to identify specific gene clusters that posed a 95 percent risk for the hallucinations and delusions associated with schizophrenia. Similarly, 7 other specific gene clusters were found, each linking to one of the classic disease symptoms.

Individually, genes have a weak link to schizophrenia, but when looked at as clusters, researchers were able to predict with 70-100 percent accuracy schizophrenia risk and symptoms.

“People have been looking at genes to get a better handle on heart disease, hypertension and diabetes, and it’s been a real disappointment,” said Dr. Cloninger. “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.”

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The National Institute of Mental Health indicates approximately 1 percent of Americans have schizophrenia. The disorder occurs equally in men and women and shows no bias based on race or ethnicity. Most individuals develop schizophrenia after age 45, and those with a family history of the disease are at the highest risk.