Highlights from Day Two: Friday, May 16, 2008
Scientists from around the world are in London for the annual International Meeting for Autism Research (IMFAR) sharing their latest research information. The goal of those in attendance is to help individuals around the world living with autism, and their families, have a better quality of care and life.
Friday, May 16
Autism Speaks' Chief Science Officer, Geri Dawson, Ph.D., opened Friday's sessions by providing a brief overview of Autism Speaks' science program and its priorities for the future. "The overarching goal of Autism Speaks is to accelerate the pace of science," said Dr. Dawson. She highlighted key Autism Speaks initiatives that will help to accelerate research including the Baby Siblings Research Consortium; the epidemiology network which is a collaboration among 30 countries; the Pan-American Initiative, a partnership with CARSO Health, NIH and Canadian Health to increase training and services for autism in North America; and the Autism Treatment Network which is currently funded in 15 hospitals nationally and working to standardize care.
"Delivering real world solutions is how we will make a difference," emphasized Dr. Dawson. "This will be achieved by collaboration with private foundations, government, the scientific and professional community and most importantly, the families."
Melatonin and Clock Genes
Keynote speaker Thomas Bourgeron, Ph.D., of Institute Pasteur, described specific genetic mutations in autism and how they may help explain why individuals with this disorder have difficulty with learning and often have significant sleep problems. Dr. Bourgeron's recent genetic studies show how several genes associated with autism influence one particular signaling pathway. They include cell adhesion molecules and scaffolding proteins located at the synapse – the junction between two neurons. This pathway is crucial for synapse formation/maintenance, and sets the correct balance between excitatory and inhibitory neural transmission in the brain – important for learning and memory. He discovered a genetic mutation found in some individuals with autism that is important for melatonin synthesis. Melatonin is involved in the establishment of the sleep-wake cycle and potentially also memory formation. Dr. Bourgeron hypothesized there may be a possible interaction between synaptic and clock genes and that their interplay could shed light on several atypical features frequently observed in individuals with ASD such as sleep problems and memory difficulties.
Autism Model Systems
Researchers from The University of Texas Southwestern Medical Center discussed the "knock-in" mouse model they created for a gene mutation associated with autism, examining the effects on the mouse's behavior. By introducing a mutated human gene into the mouse, they were able to see how it affected nerve function. The mouse showed impaired social interaction, as well as superior spatial learning skills. These "knock-in" mice may represent the first genetically accurate model of autism that is not confounded by additional neurological disorders. Models such as this will be important for future research in the cause and treatment.
Researchers representing multiple institutes discussed human brain tissue in this educational symposia. Brain tissue is a unique resource necessary to answer fundamental questions no other biological resource can. Donor families were recognized for their crucial role in this research. The new UK Brain Development Research Programme for brain donation was announced and is supported by Autism Speaks and sponsored by the University of Oxford.
The Brain Atlas Project, supported by Autism Speaks' Autism Tissue Program (www.autismtissueprogram.org) reported structural changes related to the complex clinical expression of autism in a range of ages (4-64). These developmental malformations include extra cell layers, abnormal cell clusters and increased cortical mini-columns that can contribute to the autistic phenotype. Excessive birth and migration of new brain cells was noted as well as small cell size in the nucleus accumbens in the youngest donors (age 4-7) and in all age groups in the cerebellum, striatum, amygdala and entorhinal cortex.
Another collaborative presentation by School for Mental Health and Neurosciences, Div. Cellular Neuroscience, University Medical Center Utrecht, University of Wuerzburg, and Mount Sinai School for Medicine researchers found individuals with autism have significant impairment in face processing. Imke van Kooten, Ph.D. reported changes that would affect output from the fusiform gyrus, important in face recognition and social cognition. This includes difficulty in face recognition and the use of inefficient strategies for perceiving information from other's faces. Studies using functional brain imaging have shown that, when individuals with autism look at faces, they don't activate a specialized face processing brain area located in the temporal lobe called the fusiform gyrus. Researchers discovered that autism individuals have fewer neurons, less dense neurons, and reduced volume of neurons in parts of the fusiform gyrus. These abnormalities were not found in the primary visual cortex, suggesting that the fusiform is one of the specific areas affected in autism. These studies have helped link the social impairments in autism to a specific neural system known to mediate a fundamental aspect of social behavior.
Concluding the symposia, Janine LaSalle, Ph.D. of UC Davis, discussed her study comparing autism, Rett, Angelman and chromosome 15q duplication donor brain tissue showing related genetic and epigenetic effects. "None of this could be done without brain tissue donation," said Dr. LaSalle.
Language and Communication
Researchers from Boston University studied autism and specific language impairment (SLI) and developmental disorders that have a language deficit. Their findings suggest overlap in Autism Language Impairment (ALI) and SLI over just basic language abilities, and may explain how the language difficulties in the autistic group are not necessarily related to the severity of the disorder. Additionally, relatives of children with autism performed better than those of SLI.
Researchers from University of California, Irvine looked at infertility and how its treatments may be associated with ASD. The researchers identified 715 individuals with autism and asked how many of them had been born through assisted reproductive treatment. Within this population they found an increase in the percentage of individuals that had been conceived through infertility treatments, although it did not correlate with any one type of treatment. This is the first report of an association between infertility treatments and autism risk. However, they also noted that parents who underwent infertility treatments were significantly older with higher education levels, and the children with ASD conceived through infertility treatments were presented for evaluation 10 months younger than were general children with ASD. This raises the issue of whether the association with infertility treatment was due to the fact that some parents may be more sensitive to developmental issues, given the effort they make to conceive.
David Mandell, ScD at University of Pennsylvania School of Medicine provided interesting insight into potential racial and ethnic disparities in ASD diagnosis rates. Using a dataset from the ADDM Network consisting of a cross-section of 8-year olds diagnosed with ASD, they found that black and Latino children with autism were a third less likely to have been diagnosed by the education or healthcare systems. These differences were worse among children with an IQ less than 70. Conversely, among children with an IQ above 70, higher maternal education was associated with having been diagnosed. "The disparities in diagnosis are present and may be exacerbated in the face of diagnostic complexity," Dr. Mandell concluded. "Parental knowledge and advocacy play important roles in getting children diagnosed early. Ultimately, the savvy parents in search for answers may get the diagnosis."
Presentations at IMFAR may represent unpublished and preliminary data and do not necessarily reflect the position of Autism Speaks or INSAR.
View a recap of day three, Saturday, May 17 here.
View the full press release for IMFAR 2008 here.