In honor of the anniversary of Autism Speaks’ founding on Feb 25, for the next 25 days we will be sharing stories about the many significant scientific advances that have occurred during our first five years together. Our fourth item, Convergence on PTEN Signaling Pathway, is from Autism Speaks’ Top 10 Autism Research Events of 2007.
Model systems for studying the complex and fundamentally human challenge of autism will be vitally important to solving autism because they allow researchers to study the underlying biology in a manner that is not possible in humans. Finding an animal model system with similar behavioral tendencies as humans allows researchers to study which biochemical pathways break down in autism and, most importantly, how they can be treated. In 2007, researchers added an important new model system to their arsenal, the “PTEN conditional knockout” mouse.
PTEN is a gene that encodes for a protein involved in several critical signaling pathways inside cells, including metabolism, growth and survival. To carry out its cellular duties, PTEN interacts with several other important proteins in a biochemical signaling cascade. Other proteins in this signaling pathway have previously been tied to developmental disorders such as Tuberous Sclerosis and Neurofibromatosis. In 2005, researchers found that within a small subset of individuals with autism and macrocephaly (large heads) 17% had mutations in the PTEN gene. This raised the possibility that disrupting PTEN activity, and the signaling pathways within which it functions, may result in some forms of autism. This year researchers succeeded in using complex genetic manipulations to shutdown the mouse version of the gene (PTEN) in the brain of young mice. Surprisingly, not only did these animals grow larger brains, the mice also displayed abnormal social behaviors and seizures, both of which can be features of autism.
These results provided important data supporting the emerging relevance of cellular signaling pathways to autistic behaviors, and are now focusing some researchers on specific molecules that could potentially become targets for cell-based therapeutics.
Update since this story was first run: Having discovered that disrupting the PTEN signaling pathway leads to autism-associated signs, in 2009 the researchers went on to further show that manipulation of the PTEN signaling pathway can serve as a successful treatment strategy. Making use of these same mice, they found that treatment with a pharmacological inhibitor of the PTEN pathway improved the autism-like pathology of the animals, including unusual social behaviors and seizures. Published in the Journal of Neuroscience, the newest data strengthen the case for focusing on this signaling pathway as a viable target for novel autism therapeutics.
5|25: Celebrating Five Years of Autism Science Day 3: Potential Reversal of Neurodevelopmental Disorders
In honor of the anniversary of Autism Speaks’ founding on Feb 25, for the next 25 days we will be sharing stories about the many significant scientific advances that have occurred during our first five years together. Our third item, Potential Reversal of Neurodevelopmental Disorders, is from Autism Speaks’ Top 10 Autism Research Events of 2007.
2007 saw the publication of several studies that documented successful treatment of disease symptoms in mouse models of three different neurodevelopmental disorders related to autism. Most significantly, two of three (Fragile X and Rett) involved reversal of the phenotype AFTER the mice had already become sick, suggesting that developmental disorders such as autism may be treatable in adolescence or adulthood.
In February 2007, researchers in Scotland found that they could reverse the debilitating defects and certain death in mice carrying the Rett Syndrome gene, well after the mice had regressed into the most severe stages of disease. In July, researchers at Massachusetts Institute of Technology used a mouse model of Fragile X syndrome to show that it was possible to reverse Fragile X and autistic symptoms after birth. Although the specific treatment approaches may not be directly applicable to an eventual autism treatment, the successful and entirely unexpected “rescue” of adult animals taught the world that so-called “developmental” disorders, those that begin in infancy, apparently still have a potential to be reversed later in life.
Given the behavioral overlap of these disorders with autism, even if the underlying disease-causing biological mechanisms are different, these results provided hope to scientists and families alike that we can (and will!) do the same for autism.
Update since this story was first run: These experiments changed the mindset of scientists worldwide, serving as a proof-of-principle for the many researchers now searching for pharmacological methods to treat these and other animal models of neurodevelopmental disorders. In a 2009 publication from the Proceedings of the National Academy of Science, researchers from MIT reported that a pharmacological treatment of the Rett syndrome mouse extended the lifespan of the animals and partially rescued a variety of symptoms, including irregular heart and breathing patterns. Studies such as these are paving the way for future human clinical trials.
In honor of the anniversary of Autism Speaks’ founding on Feb 25, for the next 25 days we will be sharing stories about the many significant scientific advances that have occurred during our first five years together. Our second item, Autism “Costs” Society, is from Autism Speaks’ Top 10 Autism Research Events of 2007.
Researchers in 2007 made several strides in forcing the community-at-large to face the magnitude of managing the disorder. The Centers for Disease Control and Prevention (CDC) released the first nationwide prevalence survey and the first state-wide epidemiological record- based surveys using standardized approaches, making the whole country shockingly aware that 1:150 children in America has an autism diagnosis. These studies confirmed that autism can no longer be thought of as a disorder that touches only a few people.
The suffering this causes is not easy to comprehend nor to quantify. Nonetheless, a Harvard economist managed to calculate that each year autism costs society a staggering $35 billion, and that it costs more than $3 million to care for an individual with autism over their lifetime due to their special needs. Surprisingly, adult care, not child care or early intervention and treatment, accounts for most of the costs.
As families continue to struggle to gain insurance coverage, documentation of the severity of this financial burden across the lifespan will go a long way to making our voices heard, informing policy-makers, and assisting families in planning for their future. Because of data such as this, insurance reform bills are now under way or under development in 14 states.
Update since this story was first run: Through Autism Speaks’ efforts, fifteen states – Arizona, Colorado, Connecticut, Florida, Illinois, Indiana, Louisiana, Montana, Nevada, New Jersey, New Mexico, Pennsylvania, South Carolina, Texas, and Wisconsin – have enacted autism insurance reform laws. Several other state legislatures are considering measures in 2010 to end the discrimination people with autism and their families have long endured. Visit AutismVotes.org to find out about action being taken in your state.
In honor of the anniversary of Autism Speaks’ founding on Feb 25, for the next 25 days we will be sharing stories about the many significant scientific advances that have occurred during our first five years together. Our first item, New AAP Policy and Guidelines, is from Autism Speaks’ Top 10 Autism Research Events of 2007.
After years of parents urging for earlier diagnosis and better treatments, the American Academy of Pediatrics (AAP) issued two new clinical reports in October 2007 that will help pediatricians recognize autism spectrum disorders (ASDs) earlier and guide families to effective interventions.
The first report provides detailed information on signs and symptoms so that pediatricians can recognize and assess ASDs in their patients. More specifically, the report introduces universal screening, which means pediatricians must now conduct formal ASD screening on all children at 18 and 24 months regardless of whether there are any concerns. The second report reviews educational strategies and associated therapies, which are the cornerstones of treatment for ASDs, and confirms that early intervention is crucial for effective treatment. The report states that a child diagnosed with autism should be actively engaged in intensive intervention at least 25 hours per week, 12 months per year, with a low student-to-teacher ratio allowing for sufficient one-on-one time. The report further states the importance for pediatricians to become knowledgeable about complementary and alternative medicine (CAM) therapies, ask families about current and past CAM use, and provide balanced treatment information.
The new guidelines will hopefully assure that at-risk children are finally appropriately referred without further delay. Both reports are part of a new AAP toolkit for pediatricians “AUTISM: Caring for Children with Autism Spectrum Disorders: A Resource Toolkit for Clinicians,” which includes screening and surveillance tools, guideline summary charts, management checklists, developmental checklists, developmental growth charts, early intervention referral forms and tools, sample letters to insurance companies and family handouts.
Update since this story was first run: To respond to the AAP recommendations for evaluation by primary care providers of 18 and 24 months olds with suspected ASDs, in 2009 members of Autism Speaks’ High Risk Baby Siblings Research Consortium (BSRC) published an article in Pediatrics outlining several early signs of autism that physicians and other health care providers should be aware of. The paper also identifies potential screening tools that may be used to detect early behavioral indicators. Importantly, the authors address the challenges that primary care providers face in communicating the meaning of these early signs and symptoms.