Precision and Individual Differences in Research

Understanding sensory differences 

We rely on information from our senses to understand the world around us. Many children with autism spectrum disorder (ASD) show differences in how they process sensory information that may affect their ability to engage with and learn from their world. Individuals with ASD may also have difficulty integrating information from multiple sensory modalities, such as the sound of persons talking and the sight of their moving face and mouth.

Working through the Vanderbilt Kennedy Center, we are providing the most comprehensive characterization of sensory function in children with autism to date. We are examining how sensory features relate to the social difficulties and other “core” symptoms that define autism. We are using state-of-the-art brain imaging technologies to elucidate differences in brain structure and function that may underlie differences in sensory function and broader autism symptoms, providing a compelling view into the sensory brain in individuals with autism. 

Ultimately, we hope to leverage this increased understanding of sensory function to carry out a clinical trial that tests the effect of a novel intervention that targets sensory differences in children with autism. The proposed study will incorporate research design elements and advanced analytic approaches to identify the children with ASD who are most likely to benefit from sensory-based treatment and to identify behavioral and neural mechanisms by which such a treatment may work.

Tailoring treatment methods 

  • Paul Yoder, Ph.D., Professor of Special Education

Almost all of the treatment studies I’ve conducted over 31 years examine whether individual differences prior to treatment affect the extent to which treatment works. Taking a “personalized” approach allows us to identify particular treatment methods that are best suited to individual needs and characteristics of the children we serve. 

For example, in one of our studies, we confirmed a prediction that children with Down syndrome who had initially good verbal imitation skills would learn to speak more clearly when taught with a particular method. The method involved having the therapist repeat the child’s poorly formed utterance prior to using adult pronunciation (i.e., speech recasts) rather than being asked to immediately imitate the adult models. The children with initially poor verbal imitation abilities benefited (or failed to benefit) about equally from either treatment method. 

Currently, we are testing whether an early intervention method called ImPACT facilitates communication better for infants who are greatest risk for autism and other communication disorders than infants who are at moderate risk.

Uncovering individual differences and responses

Rett syndrome (RTT) is caused by mutations in a gene called methyl CpG binding protein 2 (MECP2), which “reads” signatures embedded in each person’s DNA. In our work in RTT, we have found dramatically reduced expression of a protein called metabotropic glutamate receptor 7 (mGlu7), and have evaluated the effects of a test compound. The compound potentiates mGlu7 activity and corrects numerous deficits in cognitive, social memory, and breathing tests in animal models. 

We are now optimizing drug leads for mGlu7, which we hope can be progressed into eventual clinical trials. Importantly, we also recently found that mGlu7 levels are not decreased in all individuals with RTT, but that reductions appear to be dependent upon each person’s specific MECP2 mutation. This information is critical in helping determine which patients might respond best to an enhancement of mGlu7 activity and potentially identify individuals who may be at an increased risk of side effects with mGlu7-targeted drugs. 

This personalized medicine approach will allow us to optimize our drug development process, and we anticipate that this will provide an increased likelihood for success in RTT clinical trials.

Moving beyond one-size-fits-all interventions

I think a lot about the heterogeneity of autism spectrum disorder. Trying to understand the specific needs of subgroups of individuals uses a precision care perspective. As I do intervention research, I focus on who seems to benefit most from the intervention and why. The intervention might need to be altered or individualized to meet the needs of different groups of people. We cannot make blanket statements, and one-size-fits-all interventions are unlikely to reflect the diversity of needs.

New funding allows for exploration of nuances of Down syndrome

The Vanderbilt Kennedy Center received a 1-year grant from the National Institute of Child Health and Human Development to access Vanderbilt University Medical Center (VUMC) electronic medical record information and biological samples to develop a deeper understanding of critical issues in Down syndrome and to provide an infrastructure for future analyses.

The grant allows researchers to add targeted research questions related to Down syndrome across the VKC Intellectual and Developmental Disabilities Research Center (IDDRC). The Synthetic Derivative, which includes more than 20 years of VUMC’s de-identified electronic medical record data and BioVu, VUMC’s database of de-identified DNA samples that can be linked to data in the Synthetic Derivative, are key components as researchers begin this new path of discovery.

Sharing knowledge about Rett syndrome 

Families, caregivers, educators, clinicians, therapists, and researchers came together in October for the inaugural Rett Syndrome Education Day. The event was a rich and informative day of topics and discussion that covered research updates, medical and therapeutic intervention strategies, and Tennessee-specific programs and services.