[Mathematical learning disability: A multiple origin? Examples of Turner and Fragile X syndromes]

Area of Science:

• Neuroscience
• Developmental Psychology
• Genetics

Background:

• Mathematical difficulties are common in neuropediatric cases.
• Two models exist: genetic/modular (number sense deficit) vs. multidetermined origins.

Purpose of the Study:

• Review mathematical challenges in Turner syndrome and Fragile X syndrome.
• Investigate support for a number sense deficit in these populations.

Main Methods:

• Literature analysis of cognitive phenotypes in Turner syndrome and Fragile X syndrome.
• Examination of studies reporting mathematical abilities and cognitive impairments.

Main Results:

• Highly variable cognitive phenotypes observed, particularly in mathematical abilities.
• Number sense deficits are frequently reported, but cognitive impairments vary.
• Performance heterogeneity linked to task demands, definitions, tests, and syndrome variability.

Conclusions:

• The existence of a number sense deficit is supported but requires nuanced interpretation.
• The idea of purely modular functioning is debated.
• A global cognitive evaluation approach is necessary for these syndromes.