Huff Hall

Improving Clinical Practice and Quality of Life

SHS E-News May 2024

channell mattie


Speech and Hearing Science Associate Professors Marie Moore Channell and Laura Mattie have long been interested in the development of communication and life skills in individuals with neurodevelopmental and intellectual disabilities.

Channell directs the Intellectual DisAbilities Communication Lab, where her research team works toward a comprehensive understanding of skills that support day-to-day communication for people with Down syndrome in order to identify and develop strategies for supporting their social and academic success. In Mattie’s Development in Neurogenetic Disabilities Lab, research addresses the early development of individuals with Down syndrome and fragile X syndrome. She, too, aims toward promoting the developmental success and well-being of people with these neurogenetic disabilities.

The scholars’ shared interests have led to fruitful collaborations in the past. They led a team of researchers who used a large, national database developed by the Down Syndrome Cognition Project to characterize variability in IQ, executive functioning, adaptive and challenging behavior, and autism symptomatology among individuals with Down syndrome.

In a paper titled “Capturing cognitive and behavioral variability among individuals with Down syndrome: a latent profile analysis,” published in the Journal of Neurodevelopmental Disorders (2021, 13:16), Channell, Mattie and their co-authors describe three latent classes, or subtypes, of people with Down syndrome that emerged from their analyses.

Those in the “normative” group showed a profile of cognition and behavior that is typically represented in the literature on Down syndrome. Those in the “cognitive” group had lower cognitive scores and adaptive behaviors such as self-care and daily living skills than their peers with Down syndrome, along with high rates of autism symptoms.

Those in the “behavioral” group showed cognitive scores and adaptive behaviors similar to their peers with Down syndrome but had high rates of autism symptoms and challenging behaviors such as hyperactivity and conduct problems. Thus, with a large enough sample size, different patterns of autism symptoms and other characteristics can be seen across individuals with Down syndrome. The ultimate goal in precisely characterizing individual variability within Down syndrome is to optimize daily living through targeted treatments and interventions.

Overcoming diagnostic hurdles

Channell and Mattie currently are collaborating as principal and co-principal investigators on a study funded by the National Institutes of Health INCLUDE Project, which supports research related to the health and quality of life of individuals with Down syndrome. Working with researchers at Emory University, Johns Hopkins University and the Kennedy Krieger Institute, their study seeks to increase understanding of the co-occurrence of autism with Down syndrome to improve its diagnosis and treatment.

“There is a stereotype of people with Down syndrome as happy, social people who can’t have autism,” Channell said. “It’s more common than previously thought, but underdiagnosed.”

Interventions and therapies that people with autism receive could be a beneficial add-on to services offered to individuals with Down syndrome. Part of the problem in diagnosing autism in this population is that autism screening tools that were developed for the general population need to be adapted. To work toward the goal of developing better tools to screen for autism in people with Down syndrome, Channell, Mattie and their collaborators are conducting a nationwide survey of caregivers of youth with Down syndrome in which they are completing existing screening tools and other developmental questionnaires. The researchers will then examine and adapt the screening tools as needed so they can be used by practitioners to determine whom to refer for a full autism evaluation.

They are casting a wide net in hopes not only of representing all the varying abilities within Down syndrome, but also of including groups that are not well represented in the existing research.

“Underrepresentation is a big problem in research related to Down syndrome,” Mattie said. “We have a diverse board of stakeholders, are building relationships with the Black Down Syndrome Association, and targeting rural and Hispanic families as well.”

The questionnaires and other screening tools completed by caregivers are just one element of an autism diagnosis. There also is an in-person evaluation component, which is conducted by either developmental behavioral pediatricians or clinical psychologists who are specifically trained in autism diagnostics and assessment, as well as neuropsychological methods. The difficulty with this aspect of diagnosis is two-fold, Mattie said.

“First, the number of developmental behavioral pediatricians and clinical psychologists with this specialized training is limited, so there’s a bottleneck,” she said. “Also, while they may have expertise in autism, they don’t necessarily know about Down syndrome. So the ability to identify a true co-occurring condition is really lacking.”

Channell and Mattie may be conducting the first large-scale study using the broad screening measures doctors and clinicians give to families when autism is first suspected. Theirs may also be the first study that will explore the use of telehealth to conduct diagnostic evaluations of autism in children with Down syndrome.

“If we can figure out how to make that work, we can increase access to evaluations by specialists,” Channell said. They are working with a clinician at Kennedy Krieger, Natasha Ludwig, who will conduct the evaluations of autism in the telehealth sessions, and with Amy Cohen, director of the University of Illinois Autism Clinic, who will review and “score” the evaluations as well to ensure that evaluation tools will lead to consistent results when used by different clinicians.

With the dual focus on developing effective autism screening and diagnostic tools for individuals with Down syndrome and increasing access to specialists who are skilled in both autism and intellectual disability, Channell and Mattie intend to make a significant and lasting impact on improving the quality of life of a population that has historically been underdiagnosed and underserved. That’s good news for the individuals themselves and their caregivers, as well as the scores of clinicians who dedicate their professional lives to providing the best services possible to their clients.