Immune system may trigger schizophrenia

Schizophrenia, a mental disease, is thought to be caused by the interaction of both genetic and environmental factors. Researchers have, however, identified additional genes that confirm what scientists have long suspected - that the immune system may play a role in the development of schizophrenia.

"Knowing these specific genes are involved in the pathway leading to schizophrenia provides unique clues as to which molecular mechanisms are involved," said Roel Ophoff, professor at the University of California Los Angeles (UCLA).

Researchers have also identified genetic anomalies that disrupt the cellular pathways involved in brain development, memory and cognition, all markers of schizophrenia.

Ophoff, who led the study and his collaborators from nearly 50 institutions worldwide, performed a genome-wide scan of 2,663 people diagnosed with schizophrenia and 13,498 controls from eight European locations.

They were looking for genetic variations that are commonly present in the general population but more concentrated in those suffering from the disorder.

They found significant associations with genetic markers on the Major Histocompatibility Complex (MHC), a group of genes that control several aspects of the immune response.

The findings are significant yet not without challenge, said Ophoff, since the study aimed at the "common variants" in the human genome, said a UCLA release.

"In other words," he said, "these are not rare mutations present in only a few individuals, but these genetic variants are abundantly present in the population. Anybody could carry this variant, but that doesn't mean they will necessarily develop the disease."

"Yet, when you look at the population at large, these variants are more often present in patients than in healthy control subjects," he added.

The research appeared in the July online edition of Nature.

Last updated on Jul 6^th, 2009 at 15:37 pm IST--IANS