Schizophrenia appears to have biological roots early in life. A gene implicated inthe disease in adults has now also been linked to schizophrenia in children for the first time, strengthening evidence that the gene plays a role in the disease. The gene, NGR1, produces neuregulin, a protein crucial to brain development. The research suggests that the gene variation begins adversely affecting brain development long before the onset of psychotic symptoms, and that childhood-onset and adult-onset schizophrenia are related, occurring along a continuum.

Childhood-onset schizophrenia is rare and is marked by severe symptoms appearing before age 13. About 1 percent of the adult U.S. population has schizophrenia.

NIMH researchers led by Anjené Addington, Ph.D., and Judith Rapoport, M.D., published their results in the February 2007 issue of Molecular Psychiatry. They showed that children who have both the gene variation and schizophrenia have more gray and white matter — bundles of brain cells that process and transmit information — than usual. The researchers also showed that a normal part of brain development during adolescence, the pruning of gray matter, is greatly exaggerated in children with schizophrenia, with even larger losses occurring in those who also have the gene variation. In addition, children with schizophrenia were found to have poor social functioning even before showing symptoms of the disease.

The study also showed that some children who have the gene variation don’t develop schizophrenia or these changes in gray and white matter, suggesting that variations in additional genes may be necessary to induce the illness.

Addington AM, Gornick MC, Shaw P, Seal J, Gogtay N, Greenstein D, Clasen L, Coffey M, Gochman P, Long R, Rapoport JL. Neuregulin (NRG1, 8p12) and childhood onset schizophrenia: susceptibility haplotypes for diagnosis and brain developmental trajectories. Mol. Psychiatry 12(2):195-205. February 2007.

Source: National Institute of Mental Health