Deficits in a protein that binds RNA may be a common risk factor for disorders including schizophrenia, autism and cognitive impairment.
Nelson Freimer at the University of California, Los Angeles, Utz Fischer of the University of Würzburg, Germany, and their colleagues studied a population in northern Finland in which such disorders are particularly frequent. They discovered that many people in this region are missing a small part of a chromosome that includes the gene for the RNA-binding protein TOP3β. The mutation increases the risk of schizophrenia and several other neurodevelopmental disorders.
TOP3β interacts with FMRP, a protein associated with Fragile X syndrome and autism. In a separate paper, Sige Zou and Weidong Wang of the National Institute on Aging in Baltimore, Maryland, and their colleagues characterized these interactions and show that mutations in TOP3β or in FMRP can cause abnormal development of synapses in flies and mice.