Geneticists uncover a key clue to schizophrenia

Scientists say they have broken new ground in the study of schizophrenia, uncovering a potentially powerful genetic contributor to the mental disorder and helping to explain why its symptoms of confused and delusional thinking most often reach a crisis state as a person nears the cusp of adulthood.

Genes associated with the function of the immune system have long been suspected in schizophrenia, but scientists have been at a loss to understand the nature of the link. In a study published in the journal Nature, researchers at the Broad Institute of MIT and Harvard show that immune-related genetic variations linked to schizophrenia play a key role in prompting the "pruning" of brain connections in late adolescence.

The study offers the first clear evidence of a neurobiological basis for a disease that places lifelong burdens on patients and their families. In addition to periodic episodes of delusional thinking, schizophrenics have difficulties with working memory, planning and executive function.

Scientists have long known that schizophrenia is a heritable disorder, as it tends to run powerfully through families. But until now, scientists have been unable to link schizophrenia to specific genes or genetic variations, or show how the function of a specific gene or gene variant might lead to the brain and behavior abnormalities observed in schizophrenics.

Emory University geneticist Stephen Warren called the new study "transformational ... on many levels." Warren added, it "could, for the first time, establish a molecular explanation for the peculiar age-of-onset aspects of schizophrenia." At the same time, Warren added, the disease remains shrouded in mystery. Dr. Warren is a faculty member in the GMB and NS programs.

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