Assessment & Research

Intellectual and adaptive behaviour functioning in pantothenate kinase-associated neurodegeneration.

Freeman et al. (2007) · Journal of intellectual disability research : JIDR 2007
★ The Verdict

PKAN shows huge skill scatter—early onset hints at deeper delays, so test wide and plan personal.

✓ Read this if BCBAs working with rare neurogenetic cases in clinic or school.
✗ Skip if Practitioners who only serve common ASD/ADHD caseloads.

01Research in Context

01

What this study did

Petry et al. (2007) looked at 16 people with PKAN. PKAN is a rare brain disease that starts in childhood.

They gave IQ tests and the Vineland Adaptive Behavior Scales. They wanted to see how wide the skill range is.

02

What they found

Skills varied a lot. Some people needed only light help. Others needed full care.

Earlier disease onset linked to bigger delays. Age mattered more than the label alone.

03

How this fits with other research

Wright et al. (2024) saw the same wide spread in SYNGAP1-ID. Both papers say: test every child, do not assume.

Ohan et al. (2015) found age and IQ shape gains in ASD. K et al. echo this: younger onset means steeper challenges.

Dolezal et al. (2010) showed adaptive level does not predict behavior problems. K et al. add that PKAN also gives no single profile.

04

Why it matters

If you serve a child with PKAN, run full IQ and Vineland right away. Expect big swings in daily living, motor, and social scores. Build goals for the child in front of you, not the textbook case. Re-test each year; change can be slow or sudden.

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→ Action — try this Monday

Open the Vineland, fill every domain, then write goals that match the lowest standard scores first.

02At a glance

Intervention
not applicable
Design
case series
Sample size
16
Population
other
Finding
not reported

03Original abstract

BACKGROUND: Pantothenate kinase-associated neurodegeneration (PKAN), an extremely rare autosomal recessive disorder resulting in iron accumulation in the brain, has a diverse phenotypic expression. Based on limited case studies of one or two patients, intellectual impairment is considered part of PKAN. Investigations of cognitive functioning have utilized specific neuropsychological tests, without attention to general intellectual skills or adaptive behaviour. METHODS: Sixteen individuals with PKAN completed measures of global intellectual functioning, and participants or care providers completed measures of adaptive behaviour skills and day-to-day functional limitations. Clinicians provided global ratings of condition severity. RESULTS: Testing with standardized measures documented varied phenotypic expression, with general cognitive skills and adaptive behaviour ranging from high average to well below average. Age of disease onset correlated with measures of intellectual functioning, adaptive functioning and disease severity. CONCLUSIONS: Findings support previously described clinical impressions of varied cognitive impairment and the association between age of onset and impairment. Further, they add important information regarding the natural history of the disease and suggest assessment strategies for use in treatment trials.

Journal of intellectual disability research : JIDR, 2007 · doi:10.1111/j.1365-2788.2006.00889.x