Genetic clues to schizophrenia uncovered

Jul 30 2008

New research has found genetic flaws which scientists say are about 15 percent more frequent in people with schizophrenia.

In the largest study of its kind to date, an international team of researchers have discovered that people with schizophrenia have an "increased burden" of rare deletions and duplications of genetic material.

They say the discovery of two previously unknown areas of chromosomal deletions triples the number of genomic areas definitely linked to schizophrenia.

Dr. Pamela Sklar from Harvard University and the Stanley Center for Psychiatric Research, and colleagues form the 'International Schizophrenia Consortium team', which represents 11 research institutes worldwide, say though many have these changes in their genetic material, they are about 15 percent more frequent in people with schizophrenia and confer a greater risk for schizophrenia.

In their search for genetic variations which might be connected to the illness, Dr. Sklar and colleagues scanned the genomes of 3,391 schizophrenia cases and 3,181 controls from European samples.

They say although recent smaller studies had identified such structural genetic glitches in schizophrenia, this is the largest genome-wide study on genetic variations and may lead to improved diagnosis, treatment and prevention of such neuro-developmental disorders.

Genetic factors are thought to account for 73 to 90 percent of schizophrenia, but most of these have so far eluded detection.

The researchers found there was a significant increased number of such variations in the genes of people with schizophrenia and the size of the study allowed them to pinpoint previously undiscovered chromosomal locations associated with schizophrenia.

The researchers say just how the variations might translate into illness remains to be discovered and they warn that schizophrenia is so complex, genes alone will only ever partially explain the illness.

Experts suggest that an individual's risk of schizophrenia is dictated by other factors in life as much as by a person's genetic make-up.

The researchers say science is still a long way from having a complete picture of how various genetic flaws might work together or separately, to produce schizophrenia symptoms.

Some experts however say research needs to focus on aspects which can be changed to reduce the risk of schizophrenia and there is a danger with genetic research such as this, that many will believe schizophrenia can be predicted or eliminated.

The International Schizophrenia Consortium is composed of researchers from Cardiff University, Karolinska Institute/University of North Carolina at Chapel Hill, Trinity College Dublin, University College London, University of Aberdeen, University of Edinburgh, Queensland Institute of Medical Research, University of Southern California, Massachusetts General Hospital, Stanley Center for Psychiatric Research and Broad Institute of MIT and Harvard.

The research is published in the journal Nature.