Genes for schizophrenia found

GINA RAVENSCROFT, SCIENCENETWORK WA

Approximately 1 in 100 people will experience schizophrenia at some time in their lives. Image: alexdans/iStockphoto An illness that affects a person’s ability to think, feel and act, schizophrenia symptoms include confused thinking, delusions and hallucinations.  Approximately 1 in 100 people will experience schizophrenia at some time in their lives with the illness usually developing during the late teens or early twenties.  In a study published by the Schizophrenia Psychiatric Genome-Wide Association Study Consortium, in the prestigious journal Nature Genetics, researchers identified and replicated significant associations between schizophrenia and five novel loci and also two previously identified loci.  This is one of the largest studies of its kind and included over 50,000 people, both schizophrenia patients and healthy individuals.   The strongest new association was for a single nucleotide polymorphism (SNP) which is not located within or near to any known protein-coding genes, but is located in a region that contains the primary transcript for a micro RNA (MIR137). Micro RNAs are a relatively-recently identified group of biological regulators that modify gene expression by binding to messenger RNA and causing gene silencing.  It has recently been shown that MIR137 is involved in adult neurogenesis and neuronal maturation. The authors speculate that this variation (SNP) in MIR137 could contribute to brain development abnormalities in patients with schizophrenia. Interestingly, 17 predicted targets of MIR137 contained SNPs that were associated with schizophrenia.  In addition, this study identified four genes located within the susceptibility loci identified in the schizophrenia studies and in a study combining patients with bipolar disorder that are predicted to have MIR137 target sites.   This raises the possibility that MIR137-mediated dysregulation may represent a new mechanism underlying schizophrenia.   This study adds an interesting new candidate, MIR137, to the growing list of genetic risk factors associated with schizophrenia. Editor's Note: Original news release can be found here.