Mental illness and gene mutation studied

NEW YORK, Oct 23, 2005 (UPI via COMTEX) -- New York and California researchers have shed light on the linkage between mutated genes and cognitive-physiological changes.

A major risk factor for schizophrenia is a genetic mutation -- 22q11.2 microdeletion -- which occurs in 1 of 4,000 people. One third of people with that mutation develop schizophrenia or another psychotic disorder.

Doron Gothelf of Stanford University and colleagues administered psychological tests to children with and without the mutation and examined them again in late adolescence or early adulthood.

They found a strong effect of a particular mutation in the gene COMT. Subjects with the mutation had an abnormal decrease in the size of their prefrontal cortex, as well as lower IQs and more frequent psychotic symptoms.

In the other study, Maria Karayiorgou and colleagues at the Rockefeller University in New York examined a mouse model of schizophrenia that contains a mutation in the gene for the enzyme proline dehydrogenase, or PRODH.

They report PRODH deficiency alters the expression of the COMT gene. Interaction between these two genes modulated schizophrenia-related phenotypes in mice, such that COMT inhibition exaggerated or induced behavioral deficits in the PRODH-deficient mice.

The research appears in the November issue of Nature Neuroscience.

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