A paper published online in Nature describes the results of using bone marrow transplant (BMT) to replace faulty immune system cells in models of Rett Syndrome. The procedure arrested many severe symptoms of the childhood disorder, including abnormal breathing and movement, and significantly extended the lifespan of Rett mouse models. Exploring the function of microglia deficient in methyl-CpG binding protein 2 (Mecp2), the protein encoded by the "Rett gene, " principal investigator Jonathan Kipnis, Ph.D. and his team at the University of Virginia School of Medicine uncovered a completely novel approach to this devastating neurological syndrome. The work was funded by the Rett Syndrome Research Trust and the Rett Syndrome Research Trust UK. Rett Syndrome, the most physically disabling of the autism spectrum disorders, is caused by random mutations in the gene MECP2.
A study led by Eric Courchesne, PhD, director of the Autism Center of Excellence at the University of California, San Diego School of Medicine has, for the first time, identified in young autism patients genetic mechanisms involved in abnormal early brain development and overgrowth that occurs in the disorder. The findings suggest novel genetic and molecular targets that could lead to discoveries of new prevention strategies and treatment for the disorder. The study published in PLoS Genetics uncovered differences in gene expression between brain tissue from young (2 to14 years old) and adult individuals with autism syndrome disorder, providing important clues why brain growth and development is abnormal in this disorder. Courchesne first identified the link between early brain overgrowth and autism in a landmark study published by the Journal of the American Medical Association (JAMA) in 2003.
Dr. Christine Dollaghan, a professor at the Callier Center for Communication Disorders and the School of Behavioral and Brain Sciences, is author of a paper in the Journal of Speech, Language, and Hearing Research. The study evaluated data collected from a large sample of about 600 children. Some of the participants had specific language impairments, or SLI. She wanted to deterimine whether SLI should be regarded as a discrete diagnostic category. "One of the most basic and long-standing questions about SLI is whether children with the disorder have language skills that differ qualitatively and nonarbitrarily from those of other children or whether their language skills simply fall at the lower end of a continuous distribution, below some arbitrary threshold but not otherwise unique, " she wrote in the October article titled "Taxometric Analyses of Specific Language Impairment in 6-Year-Old Children.
Children with multiple hereditary exostoses (MHE), an inherited genetic disease, suffer from multiple growths on their bones that cause pain and disfigurement. But beyond the physical symptoms of this condition, some parents have long observed that their children with MHE also experience autism-like social problems. Buoyed by the support of these parents, researchers at Sanford-Burnham Medical Research Institute (Sanford-Burnham) used a mouse model of MHE to investigate cognitive function. They found that mice with a genetic defect that models human MHE show symptoms that meet the three defining characteristics of autism: social impairment, language deficits, and repetitive behavior. The study, published online the week of March 12 in the Proceedings of the National Academy of Sciences USA, also defines the molecular and physiological basis of this behavior, pinpointing the amygdala as the region of the brain causing autistic symptoms.
Early disruptions in serotonin signaling in the brain may contribute to autism spectrum disorder (ASD), and other "enduring effects on behavior, " Vanderbilt University researchers report. Serotonin is a brain chemical that carries signals across the synapse, or gap between nerve cells. The supply of serotonin is regulated by the serotonin transporter (SERT). In 2005, a team of Vanderbilt researchers led by Randy Blakely and James Sutcliffe identified rare genetic variations in children with ASD that disrupt SERT function. In a new study published this week in the Proceedings of the National Academy of Sciences (PNAS), the researchers report the creation of a mouse model that expressed the most common of these variations. The change is a very small one in biochemical terms, yet it appears to cause SERT in the brain to go into "overdrive" and restrict the availability of serotonin at synapses.