Adaptive behavior in primary agenesis of the corpus callosum.
Adults with ACC think they cope fine; their families see clear social deficits—collect both views.
01Research in Context
What this study did
Klein et al. (2024) asked adults with primary agenesis of the corpus callosum (ACC) to rate their own adaptive skills.
They also asked close family members to rate the same adults.
The team used the ABAS-II tool and compared the two sets of scores.
What they found
The adults saw themselves as average in daily living, social, and practical skills.
Their families saw large deficits, especially in social skills.
Only the informant scores fell below the normal range.
How this fits with other research
Alaimo et al. (2015) saw a similar self-informant gap in adults with Down syndrome.
Anbar et al. (2026) warn that switching from ABAS-2 to ABAS-3 can inflate scores.
Together these papers show that who fills out the form—and which form you pick—can hide real deficits.
Huguenin et al. (1980) tracked age gains in autistic kids, but their scores still lagged behind peers, echoing the low informant scores seen here.
Why it matters
If you only hand the ABAS to the adult with ACC, you will miss socially significant problems.
Always add a family or staff rating before you write goals or sign off on services.
One extra form can shift your whole treatment plan.
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02At a glance
03Original abstract
BACKGROUND AND AIMS: Primary agenesis of the corpus callosum (ACC) is a congenital neurological disorder characterized by the absence, either partial or complete, of the corpus callosum in individuals who do not have intellectual disability and are otherwise neurologically asymptomatic. While mild to moderate neurocognitive deficits have been observed in individuals with primary ACC using neuropsychological assessments, the impact of this syndrome on adaptive behavior remains insufficiently understood. METHODS: This study used self- and informant-ratings on the Adaptive Behavior Assessment System, Second Edition (ABAS-II) to evaluate adaptive behavior in 35 adults diagnosed with primary ACC. RESULTS: While adults with primary ACC reported adaptive functioning comparable to an age-adjusted normative sample, family informants rated their adaptive ability below norms in several skill domains, particularly social skills. CONCLUSIONS: This pattern of lower ratings by informants than self-ratings suggests adults with ACC may have poor understanding of their own behavior and its consequences. This study demonstrates that informants observe significant deficiencies in the conceptual, social, and practical aspects of adaptive behavior in persons with primary ACC, and that these deficiencies are not seen as clearly by the persons themselves.
Research in developmental disabilities, 2024 · doi:10.1016/j.ridd.2024.104862