New research strengthens evidence for ORCA, a caregiver-reported tool designed to measure communication in Angelman syndrome, and shows it aligns with widely used and validated developmental and adaptive behavior measures.
Study published in: Journal of Autism and Developmental Disorders (2026)
Quick Takeaways
The challenge: Communication is one of the outcomes families care about most, but it can be hard to measure consistently with currently available measures in clinical studies, especially across a wide range of ages and ability levels in non-verbal children and adults.
The tool: ORCA (Observer-Reported Communication Ability) captures caregiver reported observations of expressive, receptive, and pragmatic (social) communication in their loved ones living with Angelman syndrome.
What this study adds: Researchers tested whether The ORCA tool is capturing communication abilities in AS, and if the scores are tracking over time to established measures, strengthening the ORCA’s potential usefulness in clinical studies.
About the Study
The ORCA (Observer-Reported Communication Ability), is a caregiver-completed measure designed specifically to capture everyday communication in Angelman syndrome (AS). Families participating in the Angelman Syndrome Natural History Study have completed ORCA longitudinally over time, allowing for the research team to report serially on expressive, receptive, and pragmatic communication across ages and genotypes of AS. Communication is one of the most meaningful parts of daily life, and the communication challenges facing individuals and families living with Angelman syndrome is one of the most challenging aspects of the disorder, and one of the hardest things to measure in research. Most tools currently used to test communication abilities, like the Baley Scale of Infant and Toddler Develop (BSID) or the Vineland, are not granular enough to measure the true non-verbal communication abilities of those living with AS, resulting in a significant floor effect, where individuals score on the very low end of the scales. When this happens, meaningful change in communication abilities over time can be overlooked methodically on a scale, as the granularity of nonverbal communication improvements are not captured. Over 95% of individuals with AS are completely non-speaking, and communication shows up through sounds, gestures, facial expressions, the use of devices. In addition, expressive communication is only one part of the ability to communicate. Receptive and pragmatic communication is incredibly important as well, which is also hard to capture on traditional tools. Traditional in-person testing can also be challenging for those living with AS. They have severe dyspraxia and performing for an in-person test can be problematic, underestimating their natural abilities in a real-world setting.
Researchers at Duke University have been working with FAST since 2018 to develop the ORCA, which has since been additionally funded by the FDA to develop it for 12 additional neurodevelopmental disorders. To understand whether ORCA is truly measuring communication ability in AS, the research team did two things:
First, they compared ORCA scores to other well-established tools used by clinicians and therapists to measure communication and development, including Vineland-3, Bayley-4, and the Communication Matrix. In simple terms, they asked: do people with higher ORCA scores also score higher on these other measures?
Second, they used longitudinal data, meaning they looked at ORCA over time, to see whether it behaved as expected across different ages and ability levels. Does it change with time?
The results showed that ORCA scores were strongly linked to those established measures, supporting the idea that ORCA is capturing real differences in how people with Angelman syndrome communicate in everyday life. That matters because it suggests a caregiver-reported tool can provide solid, consistent information for research, without always relying on lengthy in-person assessments and may capture more granularity on the abilities of an individual living with AS that is missed on the standard measures that were not designed for Angelman syndrome or other non-verbal populations.
Why This Matters
For families and caregivers
Day-to-day observations matter. Caregiver reports can be captured in a structured, trustworthy way researchers can use.
Less burden, still meaningful. ORCA can be easier than long clinic visits while still providing useful information over time.
Improved granularity to capture all modalities of communication. ORCA utilizes not only expressive language (AAC, gestures, signs, sounds, words, etc) but receptive (e.g. the following of directions, responding to name, etc) and pragmatic (e.g. social skills), all of which are highly important in individuals with neurodevelopmental disabilities.
Improved sensitivity to measure changes in a clinical trial setting. The ability to measure change in a population that have complex communication challenges is vital. The ORCA is showing the ability to do that.
For researchers and clinicians
A better fit for Angelman syndrome. ORCA is especially relevant when most individuals are minimally to non-verbal.
More consistent research tools. A caregiver-based measure can support natural history studies and trials tracking communication in daily life and have improved granularity to detect meaningful change that is missed on traditional tools developed for neurotypically developing individuals.
For future treatments and trials
Trials need endpoints that reflect real life. This study adds valuable evidence supporting ORCA as a promising tool, an important step toward clinical trial use.
Built into an established cohort. ORCA was evaluated within the Natural History Study, strengthening its usefulness for future work, and is being used in all active clinical trials in Angelman syndrome.
FAQ
What is ORCA? ORCA (Observer-Reported Communication Ability) is a caregiver-completed measure designed to capture all levels of communication ability in Angelman syndrome across expressive, receptive, and pragmatic (social) communication.
What kinds of communication does ORCA capture? Communication as it shows up in daily life: understanding, expressing, and social interaction, including nonverbal and AAC communication.
What did this study show? It showed that ORCA scores were strongly linked to other established measures of communication and development, supporting that ORCA is capturing real differences in communication ability for individuals living with Angelman syndrome.
Does this mean ORCA can show treatment benefit in a clinical trial? This study is an important step because it supports ORCA as a valid research tool. Showing treatment benefit requires additional evidence that ORCA is sensitive to treatment-related change. Since it is currently being used in all active clinical trials we expect to see this correlation if there is a meaningful treatment effect in communication.
Why does this matter if it doesn’t change care today? Better outcome measures lead to clearer research results. That information helps researchers learn faster and gives families better answers about whether communication is changing in daily life after various therapeutic interventions.
How This Fits Into FAST’s Funding Strategy
Pillar 5: Accelerating and Preparing for Clinical Trials
FAST’s Pillar 5 focuses on the work that makes clinical studies more informative and more likely to answer the questions families care about. That includes strengthening the tools trials rely on, especially outcome measures that can detect change in ways that are meaningful in daily life. FAST Chief Science Officer Dr. Allyson Berent, and Jennifer Panagoulias FAST Head of Regulatory and Policy, were co-authored on this paper, reflecting FAST’s hands-on commitment to building the trial-readiness infrastructure the field needs alongside therapeutic progress. Communication is a priority outcome for many families, but it’s also difficult to measure consistently in Angelman syndrome across ages and ability levels, including individuals who are non-speaking. ORCA helps address that gap by translating caregiver observations of real-world communication into a structured research measure.
This study adds important validity evidence, showing ORCA aligns strongly with established assessments and behaves as expected over time. In practical terms, stronger measures help trials do their job better: they make results clearer, improve comparisons across studies, and reduce uncertainty about whether communication is changing.
Help Fund the Next Steps
Strong clinical trials depend on more than promising therapeutic approaches. They also depend on the right tools that can measure change accurately and clearly, especially for the most important outcomes families care about.
Studies like ORCA help strengthen the field’s ability to track communication in real life and interpret research results with more confidence, in a granular way that can truly measure the meaningful change that could be missed in traditional measures that were not designed for non-verbal populations. That means clearer trial readouts, better comparisons across studies, and better answers for families.
If you want to help move this work forward, consider supporting FAST’s Pillar 5: Accelerating and Preparing for Clinical Trials, which funds the trial-readiness infrastructure the Angelman field needs, including outcome measures, natural history research, and other tools that make studies more informative.
Your support helps strengthen the tools that make research results clearer for families and more informative for trials.