By Leanne Chukoskie, Autism Speaks
In 2008, Autism Speaks kick-started research in the area of non-verbal autism through its High-Risk High-Impact initiative. This year at IMFAR, Autism Speaks-funded research was featured in the Invited Educational Symposium titled Characterizing Cognition in Non-verbal Individuals with Autism: Innovation, Assessment and Treatment.
Geraldine Dawson, Ph.D., Autism Speaks’ Chief Science Officer, chaired the session and set the stage for the audience to appreciate the importance of this particular topic. An estimated 30% of individuals living with autism are functionally non-verbal, yet very little research effort was directed toward helping this group communicate their wants and needs. The inability to communicate leads caregivers and clinicians to the presumption that the cognitive skills in these individuals were low because the tests typically used to assess cognitive skill require verbal or behavioral responses that this group of individuals does not readily produce.
The first speaker was April Benasich, Ph.D. of Rutgers University, who received an Autism Speaks grant for her research. Dr. Benasich presented data on innovative new studies on 3-7 year old non-verbal children with autism. Using tasks that were designed to assess children’s capacity to identify mismatches between sights and sounds. For example, a picture of a frog might be presented with the spoken word “frog” or “cow.” The latter, obviously incorrect, pairing generates a spark of electrical activity in the brain called a mismatch negativity about 400 ms after the stimulus was presented. This sort of task can also be used to probe contextual understanding in non-verbal children by pairing, for example, the frog with “green” or “pink.” Even greater complexity can be tested by presenting sentences with errors in syntax. When heard by children who understand language, these syntax errors generate the same kind of brain potential.
Dr. Benasich and her colleagues developed a training protocol to get the children comfortable with the application and wearing of the EEG net as well as exposing them to all of the concepts presented in the experiment. The results revealed some similarities and some differences in the processing of sensory stimuli in the non-verbal children and this is not unexpected as they continue analyzing these data and also new data on older non-verbal children.
However the real power of using EEG techniques for assessing cognitive capacity is that it can tell us for an individual what we cannot get from standardized cognitive tests. Dr. Benasich presented results from individuals, some of whom were picking up the mismatches in the pictures and sounds, or sentence errors and some of whom did not.
This was the launching point for the next presentation from John Connolly, Ph.D., of Mc Master University. Dr. Connolly typically studies individuals who suffered traumatic brain injury and must be assessed to appropriately design rehabilitative therapy. He and his colleagues adapted a standard test for word comprehension called the Peabody Picture Vocabulary test (PPVT) into a tool that can be used by measuring brainwaves – no oral or manual response required. A grant from Autism Speaks allowed him to adapt his methods to work with non-verbal individuals with autism. By learning exactly what these non-responsive adolescents can and cannot understand, one can more appropriately design therapies to help them move to the next stage of learning.
Nicole Gage, Ph.D. of UC Irvine relayed her studies of both speech and sound processing in minimally-verbal children with autism using a different brain measurement tool called magnetoencephalography or MEG. One advantage of MEG for children is that nothing actually touches the child during the measurement. Although they must lie very still, there is no noise and the device resembles a fancy salon hair dryer. Using this technology, Dr. Gage and her colleagues are finding differences in very early in brain processing responses to tones and mature early in human development. These responses occur at the level of the auditory brainstem and may be at least partially responsible for the atypically responses measured to both tone and speech sounds observed by both Dr. Gage and other researchers at the later stages of brain processing in auditory cortex.
Lastly, but perhaps most importantly, Connie Kasari, Ph.D., of UCLA and the organizer of this special session presented her Autism Speaks-funded treatment research specially tailored for non-verbal children between the ages of 5 and 10 years old. Dr. Kasari uses structured play-based methods to build a scaffold and provide context for encouraging communication in these children. Her randomized controlled trial design encompasses treatment sites at UCLA, Vanderbilt, and Kennedy Krieger and involves the play based therapy especially designed for these children and also a treatment arm that includes an alternative and augmentative communication device. Dr. Kasari showed data from the group thus far – after three months of the six-month treatment trial. Not only are some individual children making incredible strides toward initiating functional communication, but overall 75% of the children in the study are responding to the therapy. Interestingly, looking back at the detailed assessments taken on the participating children upon their entry into the study no particular features distinguished the responders from the non-responders thus far.
These studies break new ground in reaching those with autism who cannot speak. However, the next steps will almost certainly be the most exciting. As more researchers and clinicians learn about these studies and are able to take advantage of the results presented, we will be better able to understand and assist individuals who are now non-verbal. These sentiments were perhaps captured best in the enthusiastic response the speakers received from the loved ones of those affected.
This Science post is by Staff blogger, Leanne Chukoskie, Ph.D.
Like most parents, the Jensens had little information about the factors that might help explain their son’s autism other than it was compounded by severe and frequent seizures. When their son was tested, however, they learned that Levi’s cells harbored a mutation that affected the way his cells produced energy. The Jensens now had valuable information to help treat their son. For individuals with his particular type of mitochondrial dysfunction, certain seizure medications can cause serious side effects.
In a way, Levi Jensen was lucky. He lived near a large research center that specializes in mitochondrial disorders which is funded by Autism Speaks to investigate the role mitochondria play in autism spectrum disorders (ASD). The diagnosis of mitochondrial disorder or dysfunction is difficult. Multiple tests, often including an invasive muscle biopsy, are required. How many other individuals with autism might benefit from a deeper understanding of how their cells use energy?
A new study released today in the Journal of the American Medical Association (JAMA) reveals that children with autism may have more trouble fueling the energy demands of their cells due to dysfunctional mitochondria. In this new Autism Speaks-funded study from UC Davis, blood samples from 10 children between the ages 2 and 5 years old and diagnosed with autism were compared with matched control samples from typically developing children. The investigators found evidence of “breaks” in the cascade of enzymes that mitochondria use to create energy in 8 of 10 autism samples, but no control samples. They found evidence of a mutation in a gene that supports mitochondrial function, also only in the autism samples. Lastly, in most of the autism samples, there were extra copies of mitochondria. The over-proliferation of mitochondria may also be a sign that individually the mitochondria are not working optimally, and are compensating for reduced function from each mitochondrion by producing more mitochondria overall.
Previous studies have shown that breaks in mitochondrial function can lead to a host of disorders, and the energy-demanding brain can be particularly affected. However, none of the previous autism studies has shown as high a proportion of impaired mitochondrial function as the current study. Cecilia Giulivi, Ph.D., the lead researcher on the study and a professor of Molecular Biosciences in the School of Veterinary Medicine at UC Davis, was drawn to research abnormal energy metabolism in autism because several symptoms of ASD overlap with mitochondrial diseases.
“We wanted to test the hypothesis in a direct way: is there a mitochondrial dysfunction in material readily available from children with full autism syndrome?” says Giulivi. The research team chose to look at white blood cells—lymphocytes—because they are a type of cell that has significant quantities of mitochondria. Drawing blood is much less invasive than obtaining a muscle biopsy, but traditionally mitochondrial function has been difficult to assess in blood because there are relatively few mitochondria in blood, compared with other body tissues. In fact, red blood cells have no mitochondria at all.
While these results are an exciting new development for both this area of research and for families, it is important to remember that this is still the edge of science and not yet a clinically-useful set of tests. However, if replicated, these tests could make screening for mitochondrial dysfunction much more accessible.
Dr. Giulivi and colleagues are already taking the next steps to follow up this research. They are studying the families of children with autism to try to understand the mechanism that causes the mitochondrial deficiency. The samples are part of a larger study (CHARGE; Childhood Autism Risks from Genetics and the Environment) in which the investigators are already measuring both genetic and environmental influences on autism risk. Adding mitochondria to that mix will be especially helpful. Dr. Giulivi was also quick to add a note of deep appreciation for all the families that participated in the study, saying “Without their participation, we couldn’t have done it!”
Indeed the enthusiasm for research participation often works both ways. The seizure medication Levi had been taking—Depakote—seemed to make Levi very drowsy. At three years old, Levi was sleeping and napping for 16 hours of the day. His mitochondrial specialist switched medication right away due to concern of an underlying mitochondrial disorder for which Depakote produced severe side effects.
The Jensens are thrilled to report that Levi now has more energy than ever, has regained words that he lost prior to the medication change, and is generally functioning at a much higher level. For Levi’s parents, Curtis and Alaina Jensen, learning about Levi’s mitochondrial disease helped them gain an understanding of metabolic functions and sparked creative ways to make special considerations for the remaining challenges Levi faced. Alaina says, “We have found that exercise has been a big key for Levi to feel good and increase his energy and stamina. It took a long time for him to build up the endurance to play, but it has been worth all the effort. With a combination of the right seizure medication, supplements, exercise and diet, we now have a very happy boy.”
Click here to view the press release on this new report.
This is a guest post by Alycia Halladay, Ph.D. and Leanne Chukoskie, Ph.D. Dr. Halladay is Autism Speaks’ Director, Research for Enivronmental Services. Leanne earned her Ph.D. at NYU’s Center for Neural Science studying the neural mechanisms that mediate vision during eye movements. During her postdoctoral training at the Salk Institute she studied search behavior in both humans and animals. A family connection as well as the curious manner in which people with autism tend to scan a visual scene led her to work for Autism Speaks as the Assistant Director of Science Communication and Special Projects. Leanne also continues her research as a Project Scientist at UCSD.
This post is by Leanne Chukoskie, Ph.D. Leanne earned her Ph.D. at NYU’s Center for Neural Science studying the neural mechanisms that mediate vision during eye movements. During her postdoctoral training at the Salk Institute she studied search behavior in both humans and animals. A family connection as well as the curious manner in which people with autism tend to scan a visual scene led her to work for Autism Speaks as the Assistant Director of Science Communication and Special Projects. Leanne also continues her research as a Project Scientist at UCSD.
Studies from “identical” (monzygotic) twins show that if one twin has autism, the other twin will also have autism about 90% of the time. Because identical twins share 100% of their genes, these data offer the strongest evidence that genetic risk factors are involved in autism. However, those numbers cannot help any particular family discern what the genes or genetic abnormalities that are contributing to their child’s autism.
A new paper in the journal Pediatrics has instigated discussion over the best way to screen patients with autism in clinical settings for genetic mutations. Current practice guidelines recommend that a standard karyotype be performed, which looks at all of the chromosomes to see if there is something clearly amiss like specific chromosomal rearrangements or Fragile X Syndrome. This technique has been in use for some time, and one of its advantages is that this test is readily available and is considered the “standard of care”. The disadvantage, however, is that many individuals with autism have no karyotype-detectable genetic abnormalities and are left uncertain about the genetic contribution to their autism.
Dr. Bai-Lin Wu and colleagues have reported on another technique, chromosomal microarray analysis (CMA) that provides a more in-depth examination of genes and chromosomes. This test has been used in research settings for many years. The benefits of using CMA for clinical practice lies in its sensitivity to detect more subtle duplications or deletions in the genetic code (known as copy number variations or CNVs) that may be too small to be detected with a simple karyotype. The difficulty, however, lies in explaining to families what the “abnormal” findings mean, specifically, if they contribute to autism risk or if their occurrence is coincidental. This is important for families trying to make informed healthcare decisions, especially given the cost of the test (typically over $1000) may not be covered by insurance. Therefore, understanding the clinical implications of these potentially significant genetic findings is going to be a critical next step for clinical geneticists.
Although there is no doubt that learning more about autism susceptibility genes is critical for the field, we have to be very careful not to give parents false hope. CMA analysis may detect genetic differences that current research shows are unassociated only weakly associated with autism. This scenario would provide an inconclusive picture of the genetic contribution to one’s autism risk. On the other hand, for some other genetic differences, the benefit to individuals may be considerable. For example, research has identified an area on chromosome 22, including the Shank3 gene, that has repeatedly been associated with autism. While currently there is no rescue or specific treatment for individuals with this mutation, families that have a child with this particular mutation can support and learn from each other at the Phelan-McDermid Syndrome Foundation (http://www.22q13.org/). Scientists hope that more can be learned from individuals with autism that have known genetic disorders such as Phelan-McDermid Syndrome, Fragile X and Rett Syndromes.
There will always be a lag between research level diagnostics and the translation of that information into a clinical standard of care. Studies like this push the envelope to raise the bar for establishing higher clinical standards and guidelines. We need more research to determine how best to use this information to benefit the families.
Sheng Y. et al. (2010) Clinical Genetic Testing for Patients with Autism Spectrum Disorders. Pediatrics. Published online March 15, 2010; DOI: 10.1542/peds.2009-1684