Mathematical skills in Prader-Willi Syndrome.
Expect profound, across-the-board math trouble in Prader-Willi Syndrome and test each skill piece by piece.
01Research in Context
What this study did
Baker et al. (2005) looked at math skills in adults with Prader-Willi Syndrome. They gave paper tests that checked number writing, times tables, and written calculation.
The team ran a small case series. Each adult completed the same math battery so the authors could map every error type.
What they found
Every adult scored far below mental-age expectations. The biggest gap was in 'syntactic' number tasks like writing 503 or solving 34 × 7.
Even simple addition facts were slow. Errors showed the adults did not grasp place value or carry rules.
How this fits with other research
Gomez et al. (2015) saw a similar pattern in kids with developmental coordination disorder. Both studies find symbolic math weaker than nonsymbolic tasks, so the issue is not just motor.
Lanfranchi et al. (2015) and Lanfranchi et al. (2022) tested number-line estimation in Down syndrome. They report scores that match mental age, but L et al. found Prader-Willi adults far under that level. The difference warns us not to lump all genetic syndromes together.
Chan et al. (2013) split Chinese first-graders into dyscalculia and low-numeracy groups. Each group had only one weak area, while Prader-Willi adults were weak everywhere. This shows a global rather than selective math deficit.
Why it matters
If you serve adults with Prader-Willi, do not assume 'life-skills math' will emerge with practice. Probe number transcoding, multiplication facts, and calculation steps early. Use error analysis to pick targets, not just standard scores. Teach place value with base-ten blocks and fold in daily fact fluency. These learners need intensive, systematic math support alongside their eating and behavior plans.
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02At a glance
03Original abstract
OBJECTIVES: This paper investigates mathematical skills in Prader-Willi Syndrome (PWS), a pathological condition because of congenital alterations of chromosome pair 15. The following questions were addressed: (1) Are mathematical skills in PWS relatively more impaired with respect to other cognitive functions (as has been repeatedly but anecdotally reported)?; and (2) What is the nature of the mathematical impairment? METHODS: The first study employed the Wechsler Adult Intelligence Scale (WAIS) and an extensive battery of cognitive tasks for which norms are known. Both batteries include a mathematical section. The second study used a theoretically motivated series of mathematical tasks specifically designed to individually assess the different cognitive components underlying mathematical skills. RESULTS: Mathematical skills were found to be the most impaired cognitive abilities together with short-term memory capacity. No specific mathematical domain was seen to be unaffected in PWS participants. The clearest deficits observed concern 'syntactic' processes in number transcoding, multiplication, number facts retrieval and calculation procedures. CONCLUSION: Failure of mathematical skills is the most distinctive feature in the cognitive profile of PWS. However, to determine whether this is indeed a specific pattern of performance related to PWS, results must be compared with those obtained with patients manifesting other genetic disorders.
Journal of intellectual disability research : JIDR, 2005 · doi:10.1111/j.1365-2788.2004.00634.x