A distinct cognitive profile in individuals with 3q29 deletion syndrome.
In 3q29 deletion, strong talk masks weak visual and daily skills—plan supports either way.
01Research in Context
What this study did
Diemer et al. (2023) mapped the thinking strengths and gaps in 32 people with 3q29 deletion syndrome.
They gave each person IQ sub-tests, language tests, and mental-health screens in one visit.
The team wanted to see if overall IQ scores could warn clinicians about later behavior or mood problems.
What they found
Verbal scores were often the strongest; non-verbal and visual-spatial scores lagged behind.
Even when full-scale IQ looked near average, hidden visual and spatial weaknesses showed up.
Cognitive numbers did not predict how heavy the psychopathology load would be.
How this fits with other research
Andrews et al. (2024) studied the same 3q29 group one year later and added daily-living scores.
They found big adaptive gaps and showed that executive-function scores, not IQ, forecasted life skills.
Together the two papers tell the same story: in 3q29, surface IQ can look okay while real-world and non-verbal skills stay weak.
Ohan et al. (2015) saw a similar IQ-adaptive split in autism, reminding us that uneven profiles cross diagnoses.
Why it matters
When you see a client with 3q29 deletion, do not trust a borderline IQ to mean mild needs.
Screen non-verbal, visual, and executive skills early and write goals for those weak spots.
Use the Vineland or similar tool to check real-life skills even if standard scores look safe.
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02At a glance
03Original abstract
BACKGROUND: 3q29 deletion syndrome is associated with mild to moderate intellectual disability as well as comorbid psychopathology such as ADHD, anxiety, ASD and schizophrenia. A greater understanding of specific profiles that could increase risk for psychopathology is necessary in order to best understand and support individuals with 3q29 deletion syndrome. The goal of this study was to thus carefully outline the strengths and weaknesses of these individuals. A second goal was to ask whether the cognitive impact of the deletion predicted psychopathology in other domains. METHODS: We systematically evaluated cognitive ability, adaptive behaviour and psychopathology in 32 individuals with the canonical 3q29 deletion using gold-standard instruments and a standardised phenotyping protocol. RESULTS: Mean full scale IQ was 73 (range 40-99). Verbal subtest score (mean 80, range 31-106) was slightly higher and had a greater range than non-verbal subtest score (mean 75, range 53-98). Spatial ability was evaluated in a subset (n = 24) and was lower than verbal and non-verbal ability (mean 71, range 34-108). There was an average 14-point difference between verbal and non-verbal subset scores; 60% of the time the verbal subset score was higher than the non-verbal subset score. Study subjects with a verbal ability subtest score lower than the non-verbal subtest score were four times more likely to have a diagnosis of intellectual disability (suggestive, P value 0.07). The age at which a child first spoke two-word phrases was strongly associated with measures of verbal ability (P value 2.56e-07). Cognitive ability was correlated with adaptive behaviour measures (correlation 0.42, P value 0.02). However, although group means found equivalent scores, there was, on average, a 10-point gap between these skills (range -33 to 33), in either direction, in about 50% of the sample, suggesting that cognitive measures only partially inform adaptive ability. Cognitive ability scores did not have any significant relationship to cumulative burden of psychopathology nor to individual neurodevelopmental or psychiatric diagnoses. CONCLUSIONS: Individuals with 3q29 deletion syndrome have a complex pattern of cognitive disability. Two-thirds of individuals with the deletion will exhibit significant strength in verbal ability; this may mask deficits in non-verbal reasoning, leading to an overestimation of overall ability. Deficits in verbal ability may be the driver of intellectual disability diagnosis. Cognitive ability is not a strong indicator of other neurodevelopmental or psychiatric impairment; thus, individuals with 3q29 deletion syndrome who exhibit IQ scores within the normal range should receive all recommended behavioural evaluations.
Journal of intellectual disability research : JIDR, 2023 · doi:10.1111/jir.12919