Assessment & Research

Adaptive behaviour deficits in individuals with 3q29 deletion syndrome.

Pollak et al. (2024) · Journal of intellectual disability research : JIDR 2024
★ The Verdict

In 3q29 deletion syndrome, executive function predicts daily-living skills better than IQ, so train EF to boost independence.

✓ Read this if BCBAs assessing or treating adaptive living skills in clients with 3q29 deletion or other rare copy-number variants.
✗ Skip if Practitioners who only serve clients with ASD and no known genetic syndrome.

01Research in Context

01

What this study did

Andrews et al. (2024) ran a case-series study on people with 3q29 deletion syndrome. They gave each person the Vineland-3 to map daily living skills. They also tested IQ and executive function. The goal was to see which score best explains the big adaptive gaps they noticed.

02

What they found

Every participant showed large, global adaptive deficits. Surprisingly, IQ did not predict how low the Vineland scores were. Executive-function scores did. The worse the EF, the lower the daily-living, social, and communication skills.

03

How this fits with other research

Diemer et al. (2023) studied the same 3q29 group one year earlier. They found verbal IQ often looks stronger than non-verbal IQ, but they still could not predict adaptive problems. The new paper steps past that limit by showing EF, not IQ, is the key driver.

Mertz et al. (2014) and Chou et al. (2010) mapped Vineland profiles in Angelman syndrome. They also saw stable, low adaptive ages. The pattern looks similar, but 3q29 deletion adds the twist that EF explains the gap, giving clinicians a clearer lever to pull.

Ohan et al. (2015) saw cognitive scores outrank adaptive scores in kids with ASD. Andrews et al. (2024) echo that IQ-adaptive split, but they go further by naming EF as the moving part you can actually target.

04

Why it matters

If you work with 3q29 deletion, stop guessing from IQ. Screen executive functions like shifting, planning, and inhibition. Build interventions that break daily tasks into smaller steps, use visual schedules, and teach self-monitoring. Strengthening EF may lift adaptive skills more than traditional academic drills.

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Add a brief EF checklist to your intake battery; pick one EF skill (e.g., task switching) and embed practice trials inside daily routines like dressing or snack prep.

02At a glance

Intervention
not applicable
Design
case series
Sample size
32
Population
intellectual disability, developmental delay
Finding
negative
Magnitude
large

03Original abstract

BACKGROUND: 3q29 deletion syndrome (3q29del) is associated with a significantly increased risk for neurodevelopmental and neuropsychiatric phenotypes. Mild to moderate intellectual disability (ID) is common in this population, and previous work by our team identified substantial deficits in adaptive behaviour. However, the full profile of adaptive function in 3q29del has not been described nor has it been compared with other genomic syndromes associated with elevated risk for neurodevelopmental and neuropsychiatric phenotypes. METHODS: Individuals with 3q29del (n = 32, 62.5% male) were evaluated using the Vineland Adaptive Behaviour Scales, Third Edition, Comprehensive Parent/Caregiver Form (Vineland-3). We explored the relationship between adaptive behaviour and cognitive function, executive function, and neurodevelopmental and neuropsychiatric comorbidities in our 3q29del study sample, and we compared subjects with 3q29del with published data on fragile X syndrome, 22q11.2 deletion syndrome and 16p11.2 deletion and duplication syndromes. RESULTS: Individuals with 3q29del had global deficits in adaptive behaviour that were not driven by specific weaknesses in any given domain. Individual neurodevelopmental and neuropsychiatric diagnoses had a small effect on adaptive behaviour, and the cumulative number of comorbid diagnoses was significantly negatively associated with Vineland-3 performance. Both cognitive ability and executive function were significantly associated with adaptive behaviour, and executive function was a better predictor of Vineland-3 performance than cognitive ability. Finally, the severity of adaptive behaviour deficits in 3q29del was distinct from previously published data on comparable genomic disorders. CONCLUSIONS: Individuals with 3q29del have significant deficits in adaptive behaviour, affecting all domains assessed by the Vineland-3. Executive function is a better predictor of adaptive behaviour than cognitive ability in this population and suggests that interventions targeting executive function may be an effective therapeutic strategy.

Journal of intellectual disability research : JIDR, 2024 · doi:10.1111/jir.13094